Karthus Buff Bug(s)

If Karthus kills an enemy while his passive is on, he will keep the buffs, and on top of that, the buff icon does not go away (although it does not give Karthus the actual buff powers) Pics: http://i.imgur.com/phDUBDp.png http://i.imgur.com/SSyUEFd.png Notice the buff icons in the first pic, and the red buff circling the second one, while not actually having the buff (Side note buffs start overlapping the second one). Replay: http://www.leaguereplays.com/replays/match/4309702/ (may take a while to open the link)