OP, you did a good thing.
I would have done the same damn thing. Not because I didn't think it was dangerous and somewhat out of hand, but because I couldn't have NOT done it, is all.
You saved a life. People will will get red in the face shouting that it was only a damn nameless kitten, which doesn't matter much at all in the grand scheme of things.
Well, guess what? Neither you nor I nor the red faced shouters matter all that much in the grand scheme of things, either, yet when some larger "hand" or circumstance comes down out of nowhere at the very last minute and saves our miserable asses, then WE are just like that kitten, no more and no less.
Grace happens. It happens in ways large and small.
You were a simple agent of grace.
You did good.