in the episode when michael shut jack and locke in the armoury they had to wait for someone to come so they could yell the combonation throught the door so they could get out, right.

now in this episode when sayid was in the armoury with the new guy, jack yell at him and says "SAYID, OPEN THE DOOR".....

now if the door could be opened from the inside why would jack and locke be stuck in there, and have to wait for someone to open it from the outside?