Invisible Blitz Fist

Yesterday during a game, the enemy Blitz's fist was invisible to me when he did his grab. He was using the Definitely Not Blitzcrank skin, and as far as I can tell the fist was only invisible to me (my friends on voice chat said they saw it as normal). Like, his arm was still visible. When his grab came out, I could see his arm extend, there was just nothing at the end of his arm. Invisible fist.