The undead soldier are his own fault for ignoring the soldiers fighting the bandits solely bc he either didnt want to help or it was a nuisance depending on each time he checked up on them. This contradicts his "i need to help people" attitude.
@GrimGriefer I think someone from deathmarch subreddit said something about satou not exactly the kind that helps every people who are in trouble. the example for that is knowing there is demon in muno barony but only acts when it matters. so its not really his own fault about ignoring the soldier, most likely he just doesn't want to bother with it, as it is not really a thing when the demon plan are still in development. I'd said he is the easy-going type, and only cared when it involved those who matters to him. correct me if I'm wrong though.