CC bar not working correctly with blind?

I was just playing against a teemo as nasus. I'd wait out the blind and then start Q'ing him directly after the CC bar was gone and I'd still be blinded for another half second or so. Idk if it's a bug or what? It might be a problem with Nasus' Q because similar shit happens with panth passive - I'll AA panth to drop his passive and follow it with a Q and it blocks both.