Truthfully, none of us knows the frame of mind of a man intent on murdering others along with himself. Maybe he waited as he did because he was having second, third, ....nth thoughts. Maybe he changed his mind, then changed it again at the last minute when he failed to get that extra bag of peanuts. I hope our FBI interrogators are "professional" enough to help him properly recollect and understand his actions, if only to provide him with the proper "closure" on this sad chapter of his life.
On the other hand, there is a school of thought that among the ways of terrorizing people is to forever leave them in the dark. Had he managed to trigger another "center fuel tank" explosion (and have we not had occasion to contemplate those in recent years?) over the Atlantic, how would the governments of the USA and France have responded? (Remember TWA 800?)
One cannot help but wonder how long it will be before someone seriously proposes a ban on the wearing of clothing on all international flights.