a chicken wing tackle is when you pull the arm back, and it has no where to go. Best example is when the player is in the back and pulling the arm backwards. Body is pushed forward, arm pulled back.
That is not what Choc was doing. Choc was using the arm to lever the player on to his back, Loche had an option to take the pressure off his arm, and that is to roll over. He was dominated in the tackle, but wouldnt submit. easy way to milk a tackle make it look awkward when the tackler grabs your arm.....
Penalty sufficient. Locke was not hurt.