Turret Shot HEALED rather than killing
(Sorry for bad quality, friend recorded it while spectating)
I was playing Sion versing a Mundo and he had just ulted and ran towards me as he was taking lots of turret damage. I ignited him, ulted into him, and flashed away. He was a single shot from death, the last turret shot hit him and he HEALED rather than killing him (His summoners were Teleport and Flash). Then he killed me.
I asked him after the game and he was unsure about it a well. Match: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2021368121/220226961