Amumu Ult Goes on CD Even if Cast Doesn't Go Through

I was playing Amumu and tried to queue up my R last moment before dying. The sound effect went through as did the ability but the animation didn't finish. I died in the millisecond the ability went off right before the animation finished. The R still went on CD despite not actually landing.

This has been historically reworked out of other Champions (notably Nami when I asked for the change; thanks to Rickless for commenting on my thread back then -- when I was BFNA -- ♥, but others as well).

Here's a recording for both proof and for reproduction purposes.

https://puu.sh/zCXSZ/9fc23ca5c1.webm

(As a side note, I know the fight was silly and stupid, there was a lot of dumb stuff going on that game and I was pushing my limits some)

But as you can see, the sound effect goes off (why I used puush over gfycat as it records the sound) but the ability does not, yet the CD goes off (wish I could show that part, but it did go on cooldown).