Hector Martin

I don't think bringing it up at all is the issue; in this case I think you jumped to assuming malicious intent. I agree it's a stupid/insensitive joke, but I think he's poking fun at those who have (unfortunately) co-opted the term "trigger" to mean "think I don't like".

You used the words "out of his way" and "deliberate"; that implies intent. Sure, intent does not matter if you look at it from purely the point of view of impact, but it does when you're trying to establish a dialogue about the issue.

The way it came across to me is that you implied he knew about psychological triggering and was at best mocking the concept and at worst deliberately trying to invoke a trigger response in certain people.

The thing is, I know for a fact that people have explained the implications of PTSD triggering to him both before and after that incident and he’s taken the view of “I don’t have any responsibility; anything I say will offend _someone_”, and refuses to change.

He definitely makes it look like he’s enjoying poking fun at people who get upset over dilutive uses of the word “trigger”. See e.g: http://www.eevblog.com/forum/chat/feminist-professor-thinks-'rigor'-is-evil/msg1442135/#msg1442135 …

[I should probably tag that link that with a CW for misogyny, dismissiveness of mental health issues, gender essentialism, and obviously his use of the word ‘trigger’.]