Invincible bandits in Fools Gold side quest.

I already got the enhanced feline sword diagram out before they glitched, but there are two bandits who chill in the cave at zero health that I can't figure out how to kill. Are there any ways to counteract this glitch?

Edit: Just tried to load a older save and did it again and the same bandits became invincible. What else is in that cave that's valuable to know what I'm missing out on?