[Gameplay] Graphical glitch with Graves remake (Huge nozzle flash)

Some of us were messing in a 1v1 custom match, between a Graves and Miss Fortune. About 40+ minutes into the game, Grave's autoattack graphics started going crazy. I've attached a video clip of what was happening. We tried selling some of the more suspicious items but we didn't follow through much in-depth.

Heres the match page: http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2007023116/236556?tab=overview