Just sit around and do other stuff for a while until it happens. The sun will rise another day if we don't start, like, RIGHT NOW. LIKE RIGHT NOW, YOU GUYS!!!!111!!!1!11!!1
Maybe he stepped in a beehive or something. Maybe he really wanted some rainbow sherbert so he had to drive to the Kroger that's 15 minutes away instead of the one that's just down the street because they don't have rainbow sherbert there. Maybe he was asked last second to attend a pre-screening of Land Before Time 17: "Yeah, We're Still Making These."
Give him like AT LEAST four minutes to do something before you get all worried. If he takes longer than four minutes then we can start sending him passive aggressive PMs or whatever, man, I don't even care.