She had food poisoning and was either puking or shatting water and all cramped up (I've never had food poisoning, what's it like?). You have to take the circumstances into account. Your buddy should explain what happened to those on the call and ask for a reschedule. When Linda returns he should first show concern for her. Then he should in a non hostile manner talk with her about how she could better handle a "similar" situation down the road. Then, bolster her, build her up and tell her about the reschedule and that she'll kill it!