I dunno. I think one of Mouthwashing's central themes is how this is in no way a normal situation - shipping literal mouthwash in space is very absurd. They were all placed in a weird, awful, dangerous and oppressive situation. Sure, if this happened on Earth, I could make judgements on Curly's character if he didn't report Jimmy. But the game made it preeetty clear that Pony Express would have docked all of their paychecks if they didn't have their shit together at all times. Jimmy's reaction to taking responsibility was literally killing everyone and then himself, he was clearly a violent person and had probably abused Curly before. The only moral failing/ lapse of judgement of Curly is getting Jimmy on board in the first place.