Riot knows about this Quinn bug, but does nothing!
When Quinn uses her ultimate, the cooldown doesn't start cycling until AFTER you use the Skystrike effect. For instance, if you stay as Valor for the full 20 seconds, it basically adds 20 seconds to the cooldown. OUCH.
This really discourages using Quinn's ultimate for roaming, and only encourages people to ditch Valor as quick as possible for that execution attack. REALLY BAD GAMEPLAY.
And Riot knows about this. But do they fix it? Nope! THEY DON'T CARE!