Aatrox Ult Bugged? Doesn't always revive if killed during animation but still goes on cd

In this clip I save ult for Darius to commit his but I "die" during the animation so it just feared the minions and didn't revive me but went on cd anyway. I've had issues dieing during the animation before but this is the first time that it feared and went on cd without the revive.

Edit: More details if they matter. In game after this happened the ult icon showed that my ult was on cd but would say "ready" if clicked on. Not sure if it matters. To be clear, the ult was put on cd.

Edit2: Happened again, but this time it doesn't show the ult going on cd in the spectator, but it did go on cd in game. https://youtu.be/8roOyfpLuDc