LLSix posted:

The medical officer can declare the captain mentally unfit for command. The senior medical officer is Doctor Moreau and he is currently enthusiastically supporting Oldcastle.

As far as ordering dangerous things goes, you're a military officer. Your superiors are supposed to order you to do dangerous things.

In theory you are required to disobey illegal orders, but if the next order is legal you're still supposed to obey it. You know of a couple of times where someone was exonerated for disobeying orders on those grounds, but the commanding officer is never punished in practice. There's definitely no legal basis for mutiny. If you do mutiny, anyone who follows you is going to be the sort of person who is willing to disobey orders which will make getting them to do what you want twice as hard. That's one of the reasons mutinies aren't usually successful in the long run.