Nothing happened to him. When I was a kid, my parents didn't socialize their dogs. So I often have to make the tough decision to leave rascal at home if a place is going to be crowded. It saves him a lot of stress and anexity. However, I still want the puppies socialized.
I feel horrible about leaving him at home, and I've explained this to you before, I believe. It's not a decision I like to make, but it happens occasionally.