I'm going to tell off an old man for making a comment about my parenting
What did he say about your parenting? Was he rude about it?
He called me a gorilla mother, I hate the guy.
That's a rather rude thing for someone to say to you. I can definitely understand why you would be upset at him for that, but you should try not to hate him or tell him off. Hating someone will not help you feel better and will just make things more uncomfortable between you two.
Wtf? I'm not upset because of that. I didn't even care.
If you aren't bothered by their comment, then I think it's best to just ignore him and not confront him. Ignoring him and taking your child elsewhere is probably the best call. Yelling at him will just make the situation worse.