As far as I'm concerned, as soon as someone starts speculating about how angry his conversational partner is he's fishing for ammunition because he's run out of salient points to bring up :U
Talking about something totally irrelevant is only going to weaken your case.

I never really understood the fairly widespread internet preoccupation with emotional state.
Quite often people have every right to be angry when discussing a serious issue, and it does not make their points any weaker unless they resort to hyperbole which is just as common from a relatively calm person.