Hey, I haven't been here for 11 months, and I think it's so cool how the new demo has just come out! At least that's how I understand the current situation. So does this one go farther than the last one that ended after you find your parents and complete two crypts?
By the way, I thought about it one day and realized that it's maybe not a "bug": It's unlikely that players will do what I'm doing (i.e. nothing), and the fact that the AI does almost nothing as well simply says that it's a stalemate! Since there's no way that the bandit can kill the stronger team members, all he can do is wait for Set to show himself.
Overall, I think it's okay, because I find the AI to be most clever in normal situations.