[seatdrummer]

There are many reasons someone could be angry. Someone might be impatient, low on sleep, frustrated they other person is being offensive. its as if one was debating flat earth theory and the other person was making ad hominem attacks, denying facts, picking at technicalities of your argument instead of the meat of your point (never say always or never because someone will find a single instance of that thing happening or not happening and suddenly they have side stepped the whole line of argument).

On the other hand if you are handling a skilled debater, and they have snuck in some false premises that have led you down a road to agreeing that abortion is objectively wrong and shouldn't be legal, that may make someone upset. It could just be that the person is upset because they feel strongly about their stance but they aren't sure where down the line of the argument they went off track. OR someone could actually be inconsistent with their thinking and when they are shown that they are wrong, they get upset.

It can't possibly just be that when you are angry you are probably are wrong, unless you only get angry when you are wrong.