In the place I work residents can be left by themselves on the toilet if they can get around on their own and are not a fall risk or have alarms. (Chair sensors, tabs etc.) I will leave them on the toilet if I know they will be okay, but if im in doubt as to wether or not they will fall I stay in the room, but give them their privacy by stepping away from the doorway. I've never had anyone fall on me...yet, and Im bound to try and stick by that. I've found people on the floor before, but none of my residents have ever fallen. If its not in the careplan that you need to stay by them, then I wouldn't worry a lot about it. Accidents happen. Just try to go on with life.