Well they mutinied and in the day that was a hanging offence, it was only because of the skill of Bligh that they didn't harm anyone. After reading books on the subject I am convinced that the mutineers fully expected Bligh and those with him not to survive.
Not only was Bligh a brilliant navigator and explorer he had a reputation for looking after his men, the exact opposite of how Hollywood portrayed him.
His mistake was staying to long in Tahiti, the charms of the Tahitian women was the main reason for the mutiny.