Vel'Koz Vision Bug

I played against a Vel'Koz one game and he beat me pretty hard. However, once he ulted me and killed me, my whole team ended up seeing him on the map for the entire game, no matter where he went. He also mentioned some sort of glitch with his ult that I don't know the details of. So, because of this vision bug, the whole game flipped around from me losing hard, to him getting killed whenever he would recall in a bush. Although he still ended up with a lot of kills at the end of the game, our team profited in free kills from the bug. I'd like to know if anyone else has seen anything similar to this.