Pretty much all hotels I have stayed at have doors with double locking mechanisms and "safety" latches. If the dead bolt is bolted from the inside, the door will not open even if the key card works. The safety latch is an extra layer of protection when the front desk screws up. Besides, I don't want the house keeping staff to walk in unannounced. As most people have said, it was most likely a case of "got the wrong room". If the people outside continued to try to get in after the warning, then I would have been on high alert. Maybe I'm just counting on the locks too much.
Regardless, I'm glad everything worked out okay. It often pays to pony up for a better hotel than to sleep with one eye open in a roach coach motel. Besides... Boogie men are the least of your worries! Idbe more concerned about picking up some nasty bugs!
The ATF should be a convenience store instead of a government agency!