Summoner's Rift, ARURF
Use of URF cannon splash damage while nowhere near the enemy.
Enemy Shen (and possibly others) were able to globally recreate the cannon's splash damage/knock-up without actually being around. Not sure if intentional or not. Discovered after killing enemy Blitz, had low health remaining and would get killed by the bugged damage. Result was enemy Shen receiving the kill credit.
Reviewing the game footage this happened with LeBlanc receiving the kill in the same way.
Upon inspection, it looks like it was due to her using her W at the exact moment of firing from the cannon which kept her at base but the splash/knock-up would still occur
Imgur link for videos: