When Sam and Dean are at the museum and Dean notices the locket is missing, Dean changes from having a binder in his left hand in the view from behind to having nothing in his hands when viewed from the front.
When the scout troop leader enters the bathroom and the lights begin to flicker, he quickly finishes and zips up. He walks away without flushing and, even though there are flush handles on the urinals and no visible automatic flush sensors, the sound of a flushing toilet can be heard.