[Gameplay] All of Quinn's autoattacks use her Crit animation.
Quinn - 3D Animated Models for League of Legends on LolKing
Quinn used to have different animations for her normal AA's and her crit AA's, now all AA's use her crit animation. I linked Quinn's 3D model on LoLKing, so you can see the difference between her basic autos (Attack 1) and her crit auto (critical attack)
Quinn also has a few other bugs as well; See all here: https://www.reddit.com/r/QuinnMains/comments/51t56g/quinn_bugs_issues_collection/