HYPOTHETICAL: You are stranded on an island with a complete stranger and you learn that this stranger has no family, no friends, and is a habitual pedophile just parolled for the third time.
1) Do you kill him right there?
After several days on the island, you go off on your own to explore - the pedophile is sleeping in camp. On the other side of the island you find an abandoned airplane (the pilot is dead on shore from a heart attack). The plane is in perfect working condition, gassed up ready to fly and with maps showing the mainland several hundred miles away.
2) Do you go back and tell the pedophile about it so you both can return to civilization... or do you just start it up and go without him? (or do you go back, kill him, THEN take off?)
Personally, I wouldn't kill him right off the bat. But I'd have to think long and hard whether to bring a pedophile back with me or whether I should just leave him to the vultures.