I confronted the hag and this led to the usual fight. She "called" for help and the little group, that I carefully bypassed afew minutes ago, appeared out of the blue. Fine.
The hag died and I wanted to see if those folks had new dialog lines. One dialog is automatically triggered but you have to talk to the others. Discussing with the one with the hammer does not go well (I forgot this element), both lines result into a fight.
And what a fight : dialog / turn hostile whatever the selected option / nevermind the first dialog with the lady offering to pay a drink once in baldur's gate / dialog unfreeze / the opponent immediatly sends you flying to the nearby chasm. No movement, no spell, no turn. The pinnacle of a well balanced tactical fight. Unfortunately I failed to find it funny, so let's rectify this : hahaha.

Now the real point.
I re-ran the hag fight with the intention to avoid the previous situation.
This time I had another surprise. As the first dialog is automatically triggered, I had the pleasure of having one character still standing in an AOE (no time/turn to go out of it) and, of course, the lady talked to him.
So I ended up with a character stuck in dialog mode, which does not stop anything, taking DoT and dying if you don't take action with your other chars.
There is a thread about the weird rules governing the state of combat engagement while in dialog, I don't want to interfere with it but I want to mention that those rules can go wrong even once the fight is over.

I think that Larian has to reassess, in-depth, the whole dialog mechanics because this is bad.