I thought I was stuck there too, you can escape if you try using the railing next to the arrow.  Point down.  The next scene has some problems btw.  One choice will loop back to the start, one choice keeps a character that probably should leave.

Oh, and last I checked you can walk through the wall on that map.  Also, one of the dead things has the wrong sprite on the next map.  (I should keep notes if I replay.)