I really would not go casting aspersions on a restaurant based on such limited evidence. A stomach virus can incubate for weeks -- he could have been infected with something a week ago and it's just bad timing/coincidence that the symptoms hit him just after eating the eggs. Also, there are plenty of other things it could be other than food poisoning or a virus. (gall bladder, my personal bugaboo....)

Anyway, hope he feels better soon.