Zed Ult Bug [GAMEPLAY]

So theres a bug where zed during his ult is not untargetable and still takes damage during his deathmark. I was spectating a match and i noticed that zed died to a blitzcrank ult while ulting. Recently as i was playing him i died to viktors ult while untargetable. Apparently it registers that hes still in the spot where he ulted so hitting an ability where he was will still hit him.

Edit: Found a video https://www.youtube.com/watch?v=0UI3c3EY17o