Possible Fix Needed For Draven's Ult

I have noticed there is a pretty significant inconsistency with Draven's ultimate in relation to other global projectiles in the game. His axes disappear upon his death. Now, I may be wrong, but I believe Ashe, Jinx, and Ezreal's ultimates all continue even if they are killed after the projectiles are launched. Why is Draven's ultimate treated differently? I thought at first it may be because his ultimate returns to him after hitting a champion/edge of the map, but Ahri's orb was recently adjusted so that it would return even if she was killed after casting. If there's a reason Draven's ultimate feels so inconsistent in comparison to other projectiles, I would be interested in why that is. However, if it is something that needs fixed, I felt I should draw attention to it so that it may be dealt with.