Oh, yeah, with hallways you shouldn't worry too much. Monster attacks usually happen when a NPC mod notices that someone's been making a lot of progress, or if the thread seems to have stalled, etc. Or if the player asks to be attacked. XD;

You shouldn't have to wait too long, since the player is supposed to be on the ball and keeping track of the area their character is in. I'd say wait a day at the most before slipping past. 8D