This is the first legitimate counterargument that's been made and we're seven layers in, that should tell everyone something.

It tells me that you see far fewer counterarguments as "legitimate" than you should.

I think textual clues outweigh extratextual extrapolation, too. The fact that the eye contact was specifically mentioned seems important, it was probably mentioned for a reason.

As I mention in a comment above, Quirrel's intent gaze is also mentioned in ch. 70, in a situation where we're pretty sure no Legimancy occurred.

Even if I was mostly wrong I would still expect more argumentation and less group ritual display from a website like this.

You refused to accept argument, and you take offense at being corrected as if making you less wrong is a hostile act.