@boag Bunny girl died because they were ambushed, and she didn't push MC out of the way or anything. It was just unfortunate that everyone else was nearby someone who could make a barrier, or could hide by nearby rocks etc; bunny girl was out in the open and got blasted as a result. I also hope you read the chapter again, because he did NOT insist going into the caves by himself; the slave brigade said they would go into the waterways to investigate since that is where the suspected ghoul infection is coming from, and Shingo says he will go since he needs to properly disinfect the area so that anyone else who goes would not catch the parasite again. And then they go find the hydra --> Shingo suggests they blow up a bit of the ceiling so they don't have to fight it head on --> he suggests they don't bother it since its a legendary dragon, and due to the situation it should finally die on it's own, meanwhile they should just plug up any more exits --> skeletons show up and they prepare for combat, while Shingo backs off a bit --> Shingo notices activity from the Hydra and tells everyone to take cover --> people put up barriers and get under cover, except Bunny girl who dies.
Blaming Shingo for Bunny Girl death in that situation is only technically true in the sense that Shingo has the highest authority of the group, thus he is responsible for everything that happens. But morally blaming him for the Hydra killing the bunny girl just makes no sense, and it almost seems like you haven't read the chapter.
Not saying that the current dragon/merc situation and him butting in like this is pretty dangerous by itself, but that whole part about the hydra seems completely different from what I read.