Sigh... a hard way to learn that hands are not hammers! Teeth are also not wire strippers.
The ratchet on the winch on my car dolly did not engage when I let go and the crank handle spun around and smacked the back of my hand.
My fault for not being more careful and make sure it did prior to fully letting go of it. the car dolly Will Bill equipped with an electric winch soon this will never happen again.