This is an act 1 scene that you probably missed because you warped to act 2 without enough long rests done to play them all. It’s… been a while since the game released and it’s written in a thread where they are commenting Minthara recruitment, which is arguably way more spoilery than this.
It happens like an hour into the beginning of the game and the spoiler tags don’t work. Jeez.
I replayed act 1 three different times going about 10 hours into each one. I’ve never encountered laz trying to kill shadowheart. I know what the scene is as I’ve seen it in passing on the internet. But I’ve never had it… dafuq?
Possibly tied to how deep into interactions with them you’ve had. If you keep them together in the party and not just at the camp, they argue a lot. Though with the bugs, it could have simply not been triggering. After patch 1, there are so many scenes I never saw my first 2 times through despite doing pretty much the same exact things in the same exact order until the goblin camp.