Attack Animation Clarification? Is that how you word it?

Uhh, noticed this a couple of games I've played now... Remember that bug with rengar when he couldn't hit his targets if he was right clicking on his target. Not sure if it's an ACTUAL bug, or if its just an animation thing (Cuz im using the Project Yi skin), but the sound goes off and everything like an attack was made, but all my character does is stutter step around the target when i right click too much (force of habit LOL.)