No, one does not cause an uncomfortable situation by mentioning that she is getting married.
Well,it seems from all accounts that he didn’t say anything at first and tried to walk away and she sensed his being uncomfortable with the situation and she kept provoking him.That sounds like someone looking for a fight to me.I don’t know any company that needs that in the workplace.
The fool allowed himself to be baited. I mean, why lose your job just because of some mentally ill woman? Nut jobs are easy to deal with if you know how.
He should have kept his cool and snickered. The more she brought it up, the more he should have snickered until it was almost a laugh.
If HR asked him about his snickering, he should have said he was thinking about a joke he read on the Internet. Nothing at all about the deranged lady, you see.