I don't believe you have.
Even if your captor is not the one who originally captured you and is being "nice" and bringing you food and water I think you are justified in using any level of force required to escape. Some people may be squeamish about this. They may have friends and family who are helping imprison people, and may not enjoy thinking of these people as bad guys. Then, there are lots of prisoners who are not behind any bars but who are no less captives.
Think about it.