According to the Players.log it seems it was map Alley3 + bootleggers encounter: Valerio Rivera + de Cesare Accardi.
The issue is that at the end of the fight when both (and all enemy units) are incapacitated the game still shows their silhouettes, and in the same time I cannot target them with attack anymore. It also freezes so my party member cannot proceed nor end turn. He has one of the bodies in a way, not sure if important. I had to reload.
As for the dialogue, I've chosen to use a skill check, so Cesare was incapacitated by his buddy before the combat.
(v14, linux)
Btw. are you sure a mere Presence suppresses one's own laughter?