[GAMEPLAY] bug, involving Mordekaiser's passive.

Basically I was playing Mordekaiser in blind pick and there was also another Morde in the enemy team, after a teamfight I notice I'm still taking damage from something, I'm getting damaged by the enemy's Morde passive until I eventually die, this continually happens after Morde is dead. I posted a video on Vimeo, to be easier to see what is wrong.