I'm pretty sure he didn't expect Kochu to be killed... he had no reason to believe this would be that cruel of a world. Also, he couldn't afford to get involved since he was a stowaway himself. They might've asked for HIS ticket if he had intervened. With that said, after occurred, he has been more involved in trying to help people instead of turning a blind eye. Had he known the consequences for Kochu, I think he would've been more active...Kochu's fate was ugly because I was all the time expecting the hippo to sneak forward and throw the ticket the hooker dropped to her. Yet he just stood there and calmly watched her get disintegrated. What a fucker! I was ready to drop the series when that happened.
About episode 5, nothing much in the plot of the episode... I cringed at the destruction of bodies and being made into food. That was creepy. An important revelation at the end of the episode though. Warp... same name they gave the main character in the first episode.