Kalista ult bug.

So last night I was playing against a Kalista/Skarner comp bot.. she was able to ult him after he died. He was dead, his dead body shot out and still knocked up/stunned my adc. Very strange. If the bonded person dies she/the support should not be able to still use the knock up. I dont have a replay program so I cant link a video. Has anyone else seen this before?