See, if you’d set it up so the maniac said “Maim this guy or I’ll strangle this kitten” then you would have gotten different responses. 
Oh god, THAT would get us into one of those animal rights debates. You know, some people saying, “…but it’s an innocent KITTY!!!”, and others, “…it’s just a fuckin’ cat. If I have to choose between a human and a cat…”
Possibly an interesting discussion, but not the one I had in mind.
I would mutilate a human long before I ever so much as kicked a cute little kitty. Chances are the human deserved it anyway.
What about an ugly pussy? 
Why do you hate cats? 
Oh. Cats… Yeah, that’s what I meant.
Oh, well, if we’re talking about, say, Steve Tyler …
Never. If he’s only maimed, I end up paying for his medical bills, food stamps, unemployment, etc.
No risk to myself? Sure there’s no physical risk but as others have mentioned I’m pretty sure that smashing a dude up with a hammer is not going to be good for my mental health. Not to mention possible legal consequences down the road. I say let him shoot the guy, but I’d ask him (very nicely) to take it outside my house first. I don’t want that mess to deal with.
Maybe if the hostage was innocent I could see myself taking the third option and attacking the captor, but that’s going to depend very heavily on the exact circumstances and what I thought I could get away with.