AITA for telling a restaurant rando he was a bad dad?

I'm physically disabled and use a wheelchair most of the time, but I'm not completely unable to walk. I can get up and walk around for a few minutes at a time, and a surprising amount of complete strangers feel like it's their god-given right to make comments about that. I've been outright accused of lying/faking my disability by randoms who don't think there is any reason to use a wheelchair other than being paraplegic.

I was out for dinner the other night and the restaurant was not the most maneuverable. At one point I needed to use the bathroom and it was looking like it would be a nightmare to get there in the chair, so I decided to just raw dog it. A rando at another table with his family saw me get up and audibly said "It's a miracle!" Usually I just try to ignore stuff like that, but it really adds up.

I looked directly at the guy and said something like "That was rude, it's completely inappropriate to comment on other people's disabilities." The guy said sorry, but very sarcastically. I raised my voice a little and told him that his behavior matters, and hopefully his son would be lucky and grow up to be a better person than him. I had definitely turned some heads at that point and felt pretty embarrassed, so my friend and I left shortly after. She didn't mind leaving the restaurant, but told me it was a low blow to basically call the guy a bad dad.