I guess what I would do is try a second day. Talk with the director about DS's experience the first day and see if some more attention from a counselor will make a difference. Maybe they can help him connect with another kid. Just having one friend might help. A lot of kids go through a rough time with this kind of transition. When I was in this situation I really struggled with how hard to push. I wanted DS to experience some social situations and sometimes if he could find a kindred soul they would work.
ITA.
Ditto.
I would also add that when I was a young adult (early 20s) I was really into physical fitness and used to lifeguard and teach kids and adults to swim at a local rec centre. In the camp's defense, I quickly learned that if a kid got their face wet (which many non swimmers fear) they would take their cue from the adult about how to react - if I made a fuss of them they would sense concern and it would exponentially increase the level of their freak out whereas if I pretended it was a game and laughed about it or ignored it they would deal with it on their own eventually. So maybe that is why no counsellor way there for him when your husband left.
But if he has another crappy day then withdraw him for sure.
