If you play the hyena sewer scene through the gallery, it's impossible to exit without closing the game completely. All scenes seem to be loaded in at once, so once you get found exiting the sewer and then try to go through the gate to the room, you'll then be caught by the hyena who's supposed to catch you later after you wake up. This leads to you AND the first hyena doing the night 20 and later scenes while skipping the first few, and ends forever stuck at the final scene because the game won't continue until Mez is where the hyena dragging him along is, who can't move because of the other hyena.
Viewing post in Bug Reports Thread - Version 1.0.x (Content Pack 3)
First, confirm that you're on the most current version of the game, 1.0.5. This was an issue that was fixed previously (though it's possible there's more to fix). Version number can be found either in the folder name or the readme.txt in the www folder.
If you ARE using the most recent version, please describe the exact sequence you're using to reproduce the bug in question. You're loading the sewer scene from the gallery, quitting out via the locker (at what point? after going how far through the scene?), and then immediately starting the scene again from the gallery and encountering scene overlap/things triggering when they shouldn't (at what point?). Doing some basic poking around I wasn't able to reproduce, but I'll try again once I have further details.