Wukong's Decoy can be used when stunned or immobilized.
I have no experienced this at all.
If this occured, it would have saved my butt in so many times in my first few games where I was noobishly relying on Decoy as a panic button.
© 2014 Riot Games, Inc. All rights reserved. Riot Games, League of Legends and PvP.net are trademarks, services marks, or registered trademarks of Riot Games, Inc.