I'd call an ambulance. It's better to be safe than sorry. Yes, he may be mad -- but at least he'll be alive to get angry. I would not tell him I'm doing it, I'd just do it.

It does sound (to me) like the seizure lasted 7 minutes and that the after affects are much more severe than normal. You can't take your FIL's word for it that he's fine -- he's obviously not, and probably lacks the mental ability to make that determination right now. If the paramedics just show up, they'll be able to check him out.