I've been doing a LP of the game recently, and encountered something pretty amusing: you can activate the lever controlling the cage from the right side of the hill, which is effectively below it (diagonally, even).
This is probably a side effect of how the tile-based engine works, but it may be worthwhile to put some rubble on that tile or something. ;)
Ha! Well, that's clearly a bug. I'll have that fixed shortly. Thanks for the report! ;)
Annnnd fixed. :)