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First, it’s highly significant that Rowling has Harry observe this exchange between Snape and Lupin:
“Ah, Severus,” said Lupin, smiling. “Thanks very much. Could you leave it here on the desk for me?”
Snape set down the smoking goblet, his eyes wandering between Harry and Lupin.
“I was just showing Harry my grindylow,” said Lupin pleasantly, pointing at the tank.
“Fascinating,” said Snape, without looking at it. “You should drink that directly, Lupin.”
“Yes, Yes, I will,” said Lupin.
“I made an entire cauldronful,” Snape continued. “If you need more.
"I should probably take some again tomorrow. Thanks very much, Severus.”
“Not at all,” said Snape, but there was a look in his eye Harry didn’t like. He backed out of the room, unsmiling and watchful.
In this exchange, Rowling is not only presenting the reader with a red herring in having Harry assume the worst of Snape’s intentions, she is also presenting them with a few clues that foreshadow not just the revelations at the end of HP: PoF but also later revelations Harry will have about Snape and his history with his father and his friends. Notably, the obvious clue in this scene is that Snape has between brewing Lupin’s Wolfsbane Potion. Secondly, from the way Snape’s “…eyes wandered between Harry and Lupin,” we can conclude that his suspicion that Lupin may be in league with Sirius and that he will attempt to lure Harry to him have been strengthened by discovering that Harry is now visiting with Lupin in his classroom after hours and having private conversations over tea. Indeed, it’s no coincidence that Sirius’s attack on the Fat Lady during the Halloween feast immediately follows this scene in Lupin’s classroom between Harry, Lupin, and Snape, as the reader learns for the first time that Snape’s reasons for being against Lupin’s appointment to the DADA position may be more complicated than him simply coveting the position for himself:
“You remember the conversation we had, Headmaster, just before – ah – the start of term?” said Snape, who was barely opening his lips, as though trying to block Percy out of the conversation.
“I do, Severus,” said Dumbledore, and there was something like warning in his voice.
“It seems – almost impossible – that Black could have entered the school without inside help. I did express my concerns whet, you appointed –”
“I do not believe a single person inside this castle would have helped Black enter it,” said Dumbledore, and his tone made it so clear that the subject was closed that Snape didn’t reply.
“I must go down to the dementors,” said Dumbledore. I said I would inform them when our search was complete.“
However, the scene in Lupin’s classroom also reveals to us one final piece of information; that is, Snape’s anxiety being in Lupin’s presence, especially when so close to the full moon (Harry also remarks on Snape sitting as far from Lupin as he can, while watching him with a “shifty eye” later in the Great Hall during the Halloween feast). It’s notable that when Snape enters the room, after taking stock of Lupin and Harry together, his focus is entirely on Lupin and ensuring that he will take his potion. He does not let his eyes wander from Lupin to the grindylow tank and he not only insists that Lupin “drink [his potion] directly,” but appears to almost nervously linger to inform Lupin that he took the extra precaution of making “…an entire cauldron full” in case Lupin “needs it.” Of course, Lupin’s own coping mechanism is also on display in this exchange, as he pointedly adopts a tone of disinterested pleasantry in the face of Snape’s nervous anxiety towards him. Lastly, we are told that Harry watches Snape “…back out of the room, unsmiling and watchful” (emphasis mine). This is our biggest clue that Harry’s narrative is misleading and, just as Snape is often incorrect when it comes to how he reads Harry’s intentions, so too is Harry mistaking Snape’s behavior as suspicious when, in fact, it is evidence of Snape’s trauma and his existing anxiety. This is a man who goes before Voldemort, widely recognized as one of the most gifted Legilimens, and lies to his face yet he refuses to turn his back on Remus Lupin when leaving his classroom. Thus, Rowling is presenting the reader with evidence of Snape’s trauma and leaving them to challenge Harry’s perspective in order to recognize the signs.
Ultimately, this scene also adds to the significance of Snape following the Trio into the Shrieking Shack in pursuit of Lupin and Sirius (something which I analyze at length, here and here). Snape is returning to one of the key sources of his trauma, fully aware that Sirius Black –who once attempted to murder or maim him using his friend and considered that a prank– will be waiting in the Shrieking Shack alongside Remus Lupin, who has not taken his potion(something Snape knows for a fact because he was delivering it to him when he saw the Marauders Map open in his empty office and learned where they were). The intriguing thing is that Snape maintains his composure so long as he feels that he has control of the situation (he very cleverly restrains Lupin first, using the advantage of surprise, as he knows he could transform soon and only then does he turn his attention to Sirius, who is wandless and thus less of an immediate threat). So, I would agree with an assessment of Snape as being someone who copes by needing control. It’s when Harry, Hermione, and Ron begin to challenge Snape, who firmly believes he’s needed there to protect them from Sirius and Remus, that we see the cracks begin to form and the signs of his trauma surface:
Hermione. Ron looked just as confused as he did, still fighting to keep hold on the struggling Scabbers. Hermione, however, took an uncertain step toward Snape and said, in a very breathless voice, "Professor Snape – it it wouldn’t hurt to hear what they’ve got to say, w – would it?"
"Miss Granger, you are already facing suspension from this school,” Snape spat. “You, Potter, and Weasley are out-of-bounds, in the company of a convicted murderer and a werewolf. For once in your life, hold your tongue."
"But if – if there was a mistake –"
"KEEP QUIET, YOU STUPID GIRL!” Snape shouted, looking suddenly quite deranged. “DON’T TALK ABOUT WHAT YOU DON’T UNDERSTAND!” A few sparks shot out of the end of his wand, which was still pointed at Black’s face. Hermione fell silent.
Interestingly, Snape is not the first to criticize Hermione as Lupin had also reverted to his more passive-aggressive coping mechanisms after Hermione exposes him as a werewolf and arrives at the same conclusions that Snape had prior to Snape’s arrival ( There was a ringing silence. Everyone’s eyes were now on Lupin, who looked remarkably calm, though rather pale. “Not at all up to your usual standard, Hermione,” he said. “Only one out of three, I’m afraid...). That being said, this is the first occasion where Snape can be seen breaking character and raising his voice and Harry even describes his expression as “…looking suddenly quite deranged” after Hermione attempts to suggest to Snape that he could be “mistaken” about Sirius. Something which she, as Snape tells her, she does not “understand” as being capable of having a triggering effect on Snape (as anyone with experience being gas-lit about their abusers or bullies might more easily be able to empathize with) for the complicated psychological associations her well-intentioned appeals on Sirius’s behalf may carry with them.
Indeed, Hermione, who is usually the most respectful and sensitive towards Snape, does not properly understand Snape’s trauma, as someone who was able to find friendship after being the recipient of Ron’s mockery in her first-year. She, like Harry (and, subsequently, like some readers) fails to empathize with Snape’s experiences because his trauma manifests in a way that they find shocking, disturbing, ugly, and, given the situation, inconvenient. Notably, when later explaining Sirius’s innocence to Dumbledore, Hermione has this to say, "He hates Sirius,” Hermione said desperately. “All because of some stupid trick Sirius played on him –” Despite knowing the gravity of the situation, and having scolded Lupin earlier in the Shrieking Shack for taking the risk he did with his friends while a student at Hogwarts, her frustration with Snape and her perspective on the situation leads even her to side with Sirius’s and Lupin’s narrative and their minimization of the “prank” as something insignificant or childish Snape should be expected to have already overcome in his life.
In many ways, I would argue that Rowling (someone who has very real and personal experience with mental illness) is presenting the reader with a challenge and a teaching lesson. They can side with the narrator, as Hermione has done in this instance, or they can read beyond it and acknowledge that Snape’s reactions are remarkably outside of his usual character and that the reason for that may be more than a mere inability to “get over” a school-boy grudge and “…some stupid trick.” That the cracks in Snape’s calm and commanding persona begin to show immediately after Hermione proposes that he could be “mistaken” about Sirius is telling. Snape cannot begin to consider the possibility that Sirius is innocent because he was not innocent when they were students and he was able to bully him, attempt to murder him, and repeatedly escape from any consequences for his actions. The crimes that Sirius was accused of (i.e. betraying the Potters, spying for Voldemort, and murdering twelve people) are blurring with the “crimes” that Snape was a personal victim of and, I would argue, this complicates Snape’s ability to rationalize. In his mind, he stands before the person who not only succeeded in humiliating and harming him for years but the person who, despite his best efforts to warn Lily, also succeeded in betraying the Potters and getting her killed. All this, only for him to have managed to escape from Azkaban and attempt to go after the boy he swore to protect in penance for his own culpability in her death. Snape cannot allow this; in his mind, he is the one who is vindicated in his suspicions of Lupin and in his certainty of Sirius’s guilt and he just cannot allow Sirius to charm his way out of any consequences for what he has done again.
In fact, I believe that this reading is strongly supported by the fact that we see the second crack in Snape’s mask of control when Harry steps up and more ardently challenges his position. Observably, Harry also can be said to have minimized Snape’s trauma and accuses him of being “pathetic” for being unable to move beyond it, and it is only when Harry raises his voice and makes this accusation that Snape again breaks from character and loses control:
Before he knew what he was doing, Harry had crossed the room in three strides and blocked the door.
“Get out of the way, Potter, you’re in enough trouble already,” snarled Snape. “If I hadn’t been here to save your skin –"
"Professor Lupin could have killed me about a hundred times this year,” Harry said. “I’ve been alone with him loads of times, having defense lessons against the dementors. If he was helping Black, why didn’t he just finish me off then?"
"Don’t ask me to fathom the way a werewolf’s mind works,” hissed Snape. “Get out of the way, Potter."
"YOURE PATHETIC!” Harry yelled. “JUST BECAUSE THEY MADE A FOOL OF YOU AT SCHOOL YOU WON’T EVEN LISTEN –"
"SILENCE! I WILL NOT BE SPOKEN TO LIKE THAT!” Snape shrieked, looking madder than ever. “Like father, like son, Potter! I have just saved your neck; you should be thanking me on bended knee! You would have been well served if he’d killed you! You’d have died like your father, too arrogant to believe you might be mistaken in Black – now get out of the way, or I will make you. GET OUT OF THE WAY, POTTER!”
The very fact that Rowling describes Snape as “shrieking” and “…looking madder than ever” is a testament to his emotional and psychological distress at this point. Harry has not only become a physical barrier between him and the only doorway out of the Shrieking Shack but he has also become yet another psychological challenge and trigger for Snape. Symbolically, Harry has once more become an associative proxy for James in Snape’s mind and we see his distress come to a boiling point when “the son of James and Lily” appears to be repaying his efforts to protect him and his friends with ingratitude and unexpected resistance. Harry, like James, also seems intent on placing his trust in Sirius. Although he does not say, one could also speculate on whether being confronted with the boy who “has his mother’s eyes” in the Shrieking Shack and having him repeat history by also defending the people who, in his mind, contributed to Lily’s death may not be additionally triggering. Regardless, we are given some suggestion to Snape’s bitterness at James for placing his faith in Sirius and we could argue that if Snape is not yet experiencing a complete flashback, he is on the verge of it. Indeed, I would go on to suggest that Harry, Hermione, and Ron’s ability to catch Snape off guard with an Expelliarmus is largely due to the fact that Snape is not himself and his emotional and psychological turmoil have left him vulnerable.
Finally, we have the scenes that transpire in the infirmary as further evidence of Snape’s trauma and the strongest example of Snape experiencing a proper flashback. First, however, we are shown Snape once again more composed as he speaks with the Minister of Magic. We also later learn when Harry and Hermione make use of the time-turner that it was Snape who took command of the situation following the chaos that ensued once Lupin transformed and bothered to conjure stretchers for them all (Sirius included). He not only brings everyone back to Hogwarts but also concocts an explanation (i.e. they were Confunded) that has the double-effect of shielding Harry, Hermione, and Ron from any consequence for their involvement and also guaranteeing that their word could not have any hope of persuading the Minister to reconsider Sirius’s guilt. Once again, he remains unfazed by Harry or Hermione’s insistence (even when Harry raises his voice again) that Sirius is innocent, largely due to this fact:
“Minister, listen!” Harry said. “Sirius Black’s innocent! Peter Pettigrew faked his own death! We saw him tonight! You can’t let the dementors do that thing to Sirius, he’s –"
But Fudge was shaking his head with a small smile on his face.
"Harry, Harry, you’re very confused, you’ve been through a dreadful ordeal, lie back down, now, we’ve got everything under control…."
"YOU HAVEN’T!” Harry yelled. “YOUVE GOT THE WRONG MAN!"
"Minister, listen, please,” Hermione said; she had hurried to Harry’s side and was gazing imploringly into Fudge’s face. “I saw him too. It was Ron’s rat, he’s an Animagus, Pettigrew, I mean, and –"
"You see, Minister?” said Snape. “Confunded, both of them… Black’s done a very good job on them…."
"WE’RE NOT CONFUNDED!” Harry roared.
However, upon Dumbledore requesting a word with the Trio, Snape’s anxiety and insecurity quickly rise to the surface again and we are given a third crack in Snape’s carefully controlled persona:
“My apologies, Poppy, but I need a word with Mr. Potter and Miss Granger,” said Dumbledore calmly. “I have just been talking to Sirius Black –"
"I suppose he’s told you the same fairy tale he’s planted in Potter’s mind?” spat Snape. “Something about a rat, and Pettigrew being alive –"
"That, indeed, is Black’s story,” said Dumbledore, surveying Snape closely through his half-moon spectacles.
“And does my evidence count for nothing?” snarled Snape. “Peter Pettigrew was not in the Shrieking Shack, nor did I see any sign of him on the grounds."
"That was because you were knocked out, Professor!” said Hermione earnestly. “You didn’t arrive in time to hear–
"Miss Granger, HOLD YOUR TONGUE!"
"Now, Snape,” said Fudge, startled, “the young lady is disturbed in her mind, we must make allowances –"
"I would like to speak to Harry and Hermione alone,” said Dumbledore abruptly. “Cornelius, Severus, Poppy – please leave us.”
Rowling tells us that Snape’s sudden lapse in control “startles” the Minister. Further, we see that Snape has become concerned that Dumbledore may have spoken with Sirius and accepted his story as true. He attempts to speak to Dumbledore first in a manner that seems dismissive, referring to Sirius’s story as a “fairytale” and then his composure cracks enough to expose his insecurity, frustration, and uncertainty when he appeals to Dumbledore outright: “And does my evidence count for nothing?” Once more, it seems to him, history is at risk of repeating and when confronted with the uncertainty of Dumbledore, he feels more of his potential powerlessness to prevent it. Thus, when Hermione interjects, he is quick to lash out at her, just as he did in the Shrieking Shack, because she is again attempting to broach the unthinkable possibility that Sirius Black could be an innocent man.
At this point, I would argue that Snape may have so thoroughly conflated the past with the present that the very idea of Sirius being found innocent of the crime that sent him to Azkaban would also be like him going unpunished for his crime of attempted murder again him, again. Thus, for Snape, the past is the present and both are so tangled in his mind that Sirius cannot be guilty of one crime and innocent of another because Sirius was never made to face any consequence for the “attempted murder” that he was guilty of. Ergo, Snape becomes incapable of making distinguishments because his trauma remains very raw, very present, and he was never given the opportunity for catharsis or healing; rather, he was forced into silence and he had to repress it. In fact, Rowling suggests as much and hints at the lasting effects of this response to his trauma when we see Snape’s hesitation in leaving Dumbledore alone with the Trio in the infirmary:
He crossed to the door and held it open for Snape, but Snape hadn’t moved.
“You surely don’t believe a word of Black’s story?” Snape whispered, his eyes fixed on Dumbledore’s face.
“I wish to speak to Harry and Hermione alone,” Dumbledore repeated.
Snape took a step toward Dumbledore.
“Sirius Black showed he was capable of murder at the age of sixteen,” he breathed. “You haven’t forgotten that, Headmaster? You haven’t forgotten that he once tried to kill me?"
"My memory is as good as it ever was, Severus,” said Dumbledore quietly.
Snape turned on his heel and marched through the door Fudge was still holding.
Harry Potter and the Prisoner of Azkaban is the book that, arguably, shows us Snape at his most rebellious. The usual dynamic between Snape and Dumbledore is strained by the presence of Lupin at the school and it becomes further imbalanced at this point when we’re shown the way that old wounds cannot always be expected to properly heal. Indeed, in cases where the trauma is suppressed or silenced, traumatic wounds can remain open; as raw and ugly/messy as when they were first received (as raw as Snape’s anger and anguish throughout the climax and resolution of Rowling’s third book is). In Snape’s case, his trauma has not just left him with scars that have begun to heal over but with open wounds that he has not been able to close. This may be largely due to the way that Dumbledore handled Sirius after his failed “prank,” as Rowling intimates when she has Snape desperately press Dumbledore on the issue. Snape has not “forgotten” the way that Sirius Black tried to kill him –indeed, Rowling has made it clear at this point that he cannot forget– and heneeds to know that Dumbledore has not “forgotten” (reiterating the word twice) what Sirius did to him.
Implicit in this exchange is the potential for further evidence of Snape’s trauma as it relates to Dumbledore, in that the reader might also infer that Snape has also not “forgotten” the way that Dumbledore handled another case where Sirius was involved and, as a result, he cannot feel secure or trust that Dumbledore will not seemingly side with Sirius (and in-so-doing, choose Sirius over him) again. Thus, the issue opens itself up to further complexity, as Snape’s trauma is not just about Sirius Black being held accountable but also about Dumbledore’s inability to hold Sirius accountable the first time and how far he has truly come in terms of his relationship to Dumbledore (i.e. any hope he might have in finding trust and loyalty with him). Dumbledore protecting Sirius, despite the reader’s awareness of his innocence, becomes for Snape a case of Dumbledore choosing Sirius over him again and once more failing to acknowledge the realityof his trauma. To bring this home, we’re again shown by Rowling that Snape does have very real insecurities and anxiety about what Dumbledore might do when Harry and Hermione are attempting to return to the infirmary after rescuing Buckbeak and Sirius and overhear this snippet of conversation:
They flattened themselves against the wall and listened. It sounded like Fudge and Snape. They were walking quickly along the corridor at the foot of the staircase.
“… only hope Dumbledore’s not going to make difficulties,” Snape was saying. “The Kiss will be performed immediately?”
Clearly still unsettled, Snape is looking for reassurance from the Minister that there can be no escape for Sirius Black (and that the consequences for his actions will be swift and immediate), even should Dumbledore attempt to come to his defense again. Unfortunately for Snape, his anxieties are realized and what follows presents us with our most compelling evidence about the unquestionable validity of Snape’s trauma. First, Rowling describes for us the extreme reaction that Snape has when he learns that Sirius Black has escaped:
He and Hermione were waiting, listening, their nerves jangling… And then, as they both took a fourth piece of chocolate from Madam Pomfrey, they heard a distant roar of fury echoing from somewhere above them…
What was that?“ said Madam Pomfrey in alarm.
Now they could hear angry voices, growing louder and louder. Madam Pomfrey was staring at the door.
"Really – they’ll wake everybody up! What do they think they’re doing?"
Harry was trying to hear what the voices were saying. They were drawing nearer –
"He must have Disapparated, Severus. We should have left somebody in the room with him. When this gets out -
Snape’s rage at his fears coming to fruition is so visceral and so absolute that Harry, Hermione, and Poppy are able to hear Snape’s “…roar of fury” through the stone floors above them. As we’re told that Sirius Black was being held in Flitwick’s office, we might assume that this is where Snape was and, upon seeing the empty office with the Minister, that this is where he most likely gave his cry of fury from. The reader is given by way of explanation that Snape’s fury comes from the “severe disappointment” that he feels in losing a potential Order of Merlin. However, I would argue that Rowling has again presented the reader with the opportunity to challenge her narrative and acknowledge that Snape’s reaction may point to a deeper source, beyond just the loss of his Order of Merlin (although there is symbolism in Snape losing the opportunity to have a tangible and public recognition for bringing Sirius Black to justice). Indeed, the very fact that Snape’s immediate conclusion is that “Potter” –whose identity we see begin to more clearly blur with James Potter in Snape’s mind as the loss of “justice” begins to cause him to flashback –and Hermione are behind Sirius Black’s escape is quite telling:
"HE DIDN’T DISAPPARATE!” Snape roared, now very close at hand. “YOU CAN’T APPARATE OR DISAPPARATE INSIDE THIS CASTLE! THIS – HAS – SOMETHING – TO – DO – WITH – POTTER!"
"Severus – be reasonable – Harry has been locked up –"
BAM.
The door of the hospital wing burst open.
Fudge, Snape, and Dumbledore came striding into the ward. Dumbledore alone looked calm. Indeed, he looked as though he was quite enjoying himself. Fudge appeared angry. But Snape was beside himself.
"OUT WITH IT, POTTER!” he bellowed. “WHAT DID YOU DO?"
"Professor Snape!” shrieked Madam Pomfrey. “Control yourself!"
"See here, Snape, be reasonable,” said Fudge. “This door’s been locked, we just saw –"
"THEY HELPED HIM ESCAPE, I KNOW IT!” Snape howled, pointing at Harry and Hermione. His face was twisted; spit was flying from his mouth.
Rowling distinctly paints a picture of a man who is so “…beside himself” that he has gone beyond the point of reason or of being reasoned with. Yet again denied the chance for Sirius Black to be held accountable, Snape “bellows” and “howls” his accusations before the Minister, Dumbledore, and Poppy with such vehemence that “spit” is described as “…flying from his mouth.” His anger becomes as symbolically raw and ugly as his trauma. As Minister Fudge even notes, Snape has lost complete control of himself and given free reign to trauma expressing itself for all to see. It is in this moment that we’re given our strongest sign that Snape’s trauma may be causing him to flashback to another Potter and another point in his life when Dumbledore, other people in authority, and even his closest friend sided with his bullies against him and his word:
“Calm down, man!” Fudge barked. “You’re talking nonsense!"
"YOU DON’T KNOW POTTER!” shrieked Snape. “HE DID IT, I KNOW HE DID IT –”
It is at this moment that we might argue that Harry Potter and James Potter begin to most distinctly merge together in Snape’s consciousness. Snape’s insistence that Minister Fudge “does not know Potter” seems to ring more true for the father who once stopped his friend from pulling off his “prank” and was hailed as a hero for it, than it might Harry Potter the boy he’s only “known” himself for three years. Just as Harry may have blended with James in the Shrieking Shack when he came to Sirius’s defense, so too may he have become an amalgamation in Snape’s mind at that moment when it seems to him that he is reliving the traumas of his past and being denied catharsis or justice. What follows is both interesting and tragic for the fact that, in many ways, it does serve to affirm for Snape that history has repeated for him and that his own trauma will go unacknowledged and he will be expected to keep his silence again (all emphasis mine):
That will do, Severus,“ said Dumbledore quietly. ”Think about what you are saying. This door has been locked since I left the ward ten minutes ago. Madam Pomfrey, have these students left their beds?“
"Of course not!” said Madam Pomfrey, bristling. “I would have heard them!”
“Well, there you have it, Severus,” said Dumbledore calmly. “Unless you are suggesting that Harry and Hermione are able to be in two places at once, I’m afraid I don’t see any point in troubling them further."
Snape stood there, seething, staring from Fudge, who looked thoroughly shocked at his behavior, to Dumbledore, whose eyes were twinkling behind his glasses. Snape whirled about, robes swishing behind him, and stormed out of the ward.
Rowling subtly draws our attention to a few key clues, first in the deliberate wording of Dumbledore when he finally steps in to intervene and then in what he says after he has Snape’s attention. Notably, Dumbledore instructs Snape to “[t]hink about what [he is] saying” before having Poppy confirm for him that Harry and Hermione had not “…left their beds” since he “…left the ward ten minutes ago.” Following Poppy’s confirmation, Dumbledore makes the very pointed observation that “[u]nless [Snape is] suggesting that Harry and Hermione are able to be in two places at once” then he needs to let the matter drop. Of course, we know that McGonagall made a special request for Hermione to have a time-turner to get to her classes and we might presume that her teachers were made aware of these special circumstances as well. Ergo, Dumbledore is very carefully making Snape aware of just how Sirius managed to escape and that he was involved in it, which presents Snape with one of two choices: either he exposes the truth and Dumbledore likely loses his position at Hogwarts or he drops the matter and keeps the truth about Sirius Black silent again. As we see, Snape looks between Minister Fudge and Dumbledore –whose eyes are “twinkling” which is often Rowling’s way of hinting to the reader the use of Legilimancy may be taking place– before he “storms” out of the ward.
So, Snape makes his choice for the sake of the war and the necessity of Dumbledore being able to maintain his strategic position at Hogwarts and returns back to keeping his silence –both about his trauma and the truth of Sirius Black– knowing now there is no chance of him being vindicated or finding catharsis. He is giving up any position of control just as he symbolically lost his control a few moments before Dumbledore’s coded revelation. In fact, I would argue that his realization of what Dumbledore has orchestrated that motivates him to find a secondary-catharsis and regain some control by revealing Lupin as a werewolf. Depending on if one reads Dumbledore as having given Snape permission to expose Lupin (which a theorize on here) or that Snape acted on his own with the potential rationalization that he was looking after the best interests of his house where Dumbledore did not (which I also discuss in more detail, here), I do find it very likely that his actions were motivated by the scene in the infirmary.
Additionally, whether the reader chooses to interpret what followed Snape “storming” out of the infirmary as adding insult to injury or not is entirely up to them, however, I personally choose to interpret Dumbledore’s words to Minister Fudge as him acknowledging the complicated history and psychological underpinnings of the situation with Sirius and how his choices have impacted Snape:
“Fellow seems quite unbalanced,” said Fudge, staring after him. “I’d watch out for him if I were you, Dumbledore.”
“Oh, he’s not unbalanced,” said Dumbledore quietly. “He’s just suffered a severe disappointment."
The “severe disappointment” that Dumbledore speaks of is not just the symbolic loss of the Order of Merlin that would have meant a public acknowledgment of him bringing his bully to justice. It’s also the harsh reality of having Dumbledore side with another “Potter” and his friend in helping his childhood bully escape from facing any consequences again, as no matter how innocent Sirus Black might have been of one crime in Snape’s mind he will always still be guilty of “attempted murder.” Therein lay the source of Snape’s trauma; he is a victim who has never been able to have his bullies held accountable and he has been perpetually silenced and denied the catharsis of justice or recognition –which is why James changing is not a good argument, and will never be a good argument, as it only seeks to derail from the reality of how trauma functions for people whose wounds remain as raw, untreated, and left to fester as Rowling shows us Snape’s are in Harry Potter and the Prisoner of Azkaban.
