Nice shot! I wouldn't say luck. It's a result of practice. You're prefocused and waiting for the proper moment to completely press the shutter release.
Ouch! Looks like a shot off the knuckles to me.... Even if it missed & was off the throat of the bad, I'm sure some tremors were sent up his arms...
My guess is a little of both good timing & the luck as good of timing one developes with a large lag timing the Uzi has... Consistant good luck is a product of practice...
A beauty fer sure...
