[GAMEPLAY] Warwick ult bug with ga

I was spectating my mate and saw this happen:

Warwick was low, had ga on him and ulted an enemy, WHILE ulting he died, but his ult still dealt the full dmg over a few seconds AFTER he died. I dont think the dmg should continue if he gets killed in his ult duration...

How to reproduce: Kill an ww who is on low hp while he is ulting an enemy (and ww has to have ga on him)