It has been a while, but if I recall, there's no "breakaway" rolls or things like that. You just move away on your figure's activation.
Not exactly -but James got it right. If Hans succeeds with his Harpoon attack, there's no breaking away from him -at least not until Han's is dead.
But keep in mind that if the harpooned APE (or MI-13) character dies as a result of the attack; Hans must spend 1 AP to remove the harpoon.