[Gameplay] Karthus passive/ult bug: ult is disabled too soon!

As you can see, Karthus' ultimate is disabled 0.5 - 1.0 seconds before it should be. It is a 3s channel, so it shouldn't become disabled until the last 3 seconds of his passive duration; his passive lasts just over 7 seconds, so it should be AVAILABLE for the first 7-3=4 seconds of his passive; however, it is only available for 4.30-1.03=3.27 seconds. This is a difference of 0.73 seconds when Karthus SHOULD be able to activate his ultimate, but he cannot. 00.00: begin 01.03: karthus death 04.30: ultimate becomes inactive 08.13: karthus passive ends