AITAH for calling a woman(40+F) a whore after I(39F) caught her touching my autistic son(19M) at a restaurant?

I (39F) have a son (19M) who is autistic. He sometimes struggles with anxiety and takes time to get used to new people. He's very shy and I'm one of the few people he's most comfortable with. Yesterday I took him out to a restaurant for a meal just the two of us like we usually do. After we finished our meal I went to the ladies room and when I came back there was a woman not much older than me flirting with him and I don't mean subtle flirting, she was standing next to him rubbing his shoulders while he sat there looking uncomfortable.

I froze for a second not sure how to react. Then I saw him flinch when she tried to move her arm closer to his neck. That's when I lost it. I asked her what the hell she thought she was doing. She asked who I was and I told her I was his mom. She tried to deflect with Oh you've raised such a fine gentleman and other BS like that. I told her to shut it because I saw exactly what she was doing.

She tried to act like I was the one being crazy. Her hand was still on his shoulder (not rubbing anymore, but still there). I told her to take her hands off my boy. She did, but then got angry and said I was making a scene for no reason and that I should "learn some manners." By this point most of the restaurant was staring at us. I snapped and told her she should learn some class and stop whoring herself out to guys my son's age. She gasped, called me the b word and said I was white trash and basically started off on a whole rant. I ignored her gathered our things took my son's hand, and left the restaurant.

We joked about it later, but I'm still pretty upset about the whole thing. Not one person would step in to defend my boy when I was gone and now I'm even more genuinely terrified of something like happening again. Aitah?