I have a similar problem, and SE's support is pretty darn awful so far. My physical security token stopped working and email support told me to use chat or call, and I got the same "no agents are available" message after waiting 2 hours, like your brother did. I did some searching and it seems that this sometimes happens, but not always, so I am going to keep trying. It is very discouraging though and should not happen at all! Combined with the login issues we had the first week, I am starting to think that queues are a really difficult thing for SE.

I believe there is some sort of emergency password for removing the phone token app, though it sounds like your brother doesn't have one? It could be handy for if there is a next time, though.