I'd LIKE to try to educate them since they obviously have more kittens in the same situation
You can't education stupid, irresponsible pet owners, and he's definitely one!! I'd take the kitten in and if he asks where it is, say you haven't seen it. Just from what you told me, this guy doesn't like cats. Accidentally got out HOW MANY TIMES???? PUHLEEZE!!!

Please do this cat a favor and give it a good home. If you give him back to that jerk, God only knows what would happen. I'd sleep better at night knowing that precious grey boy is warm, fed and above all, SAFE!!!