Sion Gameplay Bug Preventing Assists

I recently played a game as Sion where I would not get any assists if the kill happened when I was dead, including during his passive.

How to recreate:

1. Play a game as Sion
2. Hit enemy
3. Die
4. Have ally get kill before assist timer ends

I don't have a screenshot, but I am going to get one in a custom later. I ended the game with 1 assist, the only one that I got while I was still alive. I am 100% sure that I should have gotten at least 5 more assists.

Please fix this bug, as it makes Sion basically unplayable if you don't get assist gold.