Wowsa! I'm actually glad you didn't hit him although I know you wanted to. Something tells me that the second you would have laid hands on him, his mom could have flipped on you. Just by her allowing him to act out tells me she isn't very consistent and isn't aware of appropriate behavior....
BUT this isn't a reflection of B.O.B. at all..this was with that particular person and her bad decisions in customer service, appropriate behavior, and child-rearing.
I would have found out if she was the owner/manager and if not, I'd have reported that immediately. By speaking to the manager/owner (if it wasn't her), that would have given you a more accurate idea of how this particular business owner runs her business. But don't apply this unique experience to all B.O.B.s..it's not fair.