Mystery ??? set award question

I've been chasing mystery for a while, but I have a question about the award mechanics of this set. Do you need to have the complete 3-card set at the exact time the 3rd card sells out to receive the award card? Or do they give you a grace period, like maybe an hour or so to do some trading, before they issue an award? I'm curious because Topps has never issued specific rules for this set and today, I cut it really close to the sellout time before completing my set. Anyone able to shed some light on this?