I locked me and my (now ex) gf in the hall of our flat once!
Got in, closed door wee yale lock locked into place and done the big key lock as we were in for a while, went into the big bedroom and i hung the keys up, left the room and closed the door, as i done so i heard the wee yale lock click... oops!  (Flat was rented out as 2 bedroom, studentish, so doors had locks on them)
Were stuck in the hall/bathroom/kitchen and empty living room for about 3 hrs before the landlord could come over! Only had a spare big lock key, so had to jmmy the small yale lock with a big sheet of hardish plastic... was a proper pain!  
I know it doent really have anything to do with or help your situation... but i guess it means i feel your pain! lol