[GAMEPLAY] Warwick's ultimate still working after death.

I was playing ARAM; during a teamfight, I killed Warwick but he casted his ultimate briefly before dying... the effect of suppression kept going for all the spell duration even if Warwick was dead right after casting it.

This happened like 2, 3 times, in the same way:

1. he casts his ultimate
2. he dies right after
3. the suppression effect of his ultimate keeps going on the target.

Unfortunately, I have no video to share.