Quinn passive potential bug

As I have been playing through most of my games, with Quinn's passive you would go to do the auto attack with the harrier passive on an enemy, and if you were to cancel this auto attack accidentally and still want the attack to go through, you go to do your next auto attack and the attack is normal. It resets the passive on an approximate 3 second cooldown, then the auto after the normal auto attack, the harrier passive will go off again. It i believe is a repeatable process with any harrier auto attack until the passive is lifted off the target. Can anyone clarify if this is a Quinn bug or if it is just an actual thing with her passive that I may have overlooked? As I have looked into Quinn's kit I see nothing saying about this part of her passive. So it must be a bug!