I'm sure this has been reported before, but Shaco's Q sometimes does not make him invisible in ARAM. Enemies can still see him and attack him while "invisible". And these enemies do not have "Magical sight" active. I checked. Yesterday I played a game where a Shaco used Q to get in range of a low Health Kai Sa who had no means to reveal him, but she was still able to auto attack him and use her Q on him.
Some more info:
Patch: 9.23 (and all before it)
Server: EUW (but I'm sure it's on all servers)
Type of Bug: In-game
Game replay: EUW1-4311546290
I have screenshots and the replay file, but I can't seem to upload them to the forums.