I'm not sure of the situation, but I think hostility is appropriate in a personal situation.
If someone is falsely accusing you of something, or portraying your actions as something they're not, it's best to immediately strike back. Don't waste your time refuting -- that just makes you look guilty. Call out their tactics and absolutely verbally smack them.
They're expecting you to fall into their trap and debate the false point. By going for the throat, and going after the methods, you deny them that, and put them back on their heels.
However, there are legal and professional situations that, due to what can be lost, may need to be handled differently. I'm less sure about those. I would advise lots of common sense, and avoiding situations and people that can bring about this kind of thing in the first place.