Bug Report: Vi and Morgana

So I was playing a game earlier and noticed an interesting bug. I ulted the enemy Yasuo as Vi and the allied Morgana used her Black Shield on him in the middle of my ult. What happened was that Yasuo kept flying in the air and was actually cc'ed for longer than normal. What I am theorizing is that since the Black Shield was put into affect as Vi was pushing Yasuo up, it then interrupted the cc of pulling him back down to the ground. This netted in Yasuo flying extremely high into the sky.

Anyone else seen this bug? And Sorry I didn't search the forums first to see if it existed.