client undead ghost player

I saw someone glich moving, after I killed him and he got back this is what I see: him glitch dieing, while he himself is standing in the background

video:
https://youtu.be/be_rQ_YAynk

Note, this is not the same as MC-37586 since the "ghost" player was an actuall player, and when killed created the real dubble, and the effected player never left the game