Invisible ashe ult [GAMEPLAY]

I recently finished playing a ranked game against a Woad Ashe. At level 6, she "ulted" me. The particles around the arrow (sparkles) appeared, the sound played, but the arrow itself didn't appear. Though I won the game, Ashe managed to get quite a few kills off this bug. Apparently, the enemy team could see it, but the other members of my team couldn't (I asked them all). Please look into this. Thanks Riot.