What the hell is this? (Lux ult rotation bug)

Best I can tell is that the ult model/animation is supposed to be in a straight line from the core, parallel to the ground.

However on the new Summoner's Rift there are small inclines that angle the player model ever so slightly that cause the effect you're seeing here because Lux's ultimate animation is locked to be emanating from her core in a straight line.

I don't know if that made any sense but I'll try to replicate the bug and I'll make a further bug report post if this one doesn't catch on.