Vi's Q malfunction after Kalista Ult Impact

So I went along today with my normal business, ganking and such until one Kalista and Leona warded just in time to see me coming. Q charged, I dove in. Quickdraw Kalista activated her ult and Leo was sent hurtling at me mid-Q travel. It was epic, considering what else was going on. But the trouble lay with my Q afterward as if my gauntlet's were broken. Cooled down, etc. it would not reactivate. I had more than enough mana, no debuffs - it simply wouldn't work.

Shell