I didn't get a screenshot of this, but the other day I played two Normal matches as Neeko with an Aphelios on my team. I noticed the visual bug when I disguised myself as Aphelios and started to walk around. Instead of the normal walking animation, he slid around in the T-pose. It was actually really funny, but should probably be fixed. I did recreate the bug in the second match as well.
I did not see this happen with anyone else, but I also wasn't paying as much attention after the first minion waves crashed. I actually don't even recall if I ever disguised myself as Aphelios later on in the match. I did make sure that another player was seeing the graphic error as well, and they confirmed in chat.