Read point 3: "On September 22, you admitted to these attacks in writing."
Compare the dates. According to the letter, his disclosure came after the account was suspended. Implying that they did detect the attack before he admitted to it.
You're using uncorroborated dates in a document that's clearly worded to paint the student in the worst light possible to infer a 'detection' which it doesn't mention and for which there is no evidence. You're then sharing your inference as documented fact. That's a smear.
The letter doesn't say that. No other sources say that. You're the only one saying that.
I never said that it was not a case of responsible disclosure. I simply don't know, the evidence at this point seems insufficient to support either conclusion.