Under the Unfair Play Rule – 13.2.1 (vi) Retaliation:

Sanction:  Penalty Pass and the player is cautioned.  If the action is considered to be serious the player is given an official warning or suspended.

Scenario – Blue WD contacts the Yellow C and the umpire awards a penalty pass.  At the same time the Yellow C retaliates by shrugging of the Blue WD as a result of the contact.

The umpire should hold time and issue a caution to the Yellow C, or if the action is deemed serious enough an official warning or a suspension is issued.

The Blue WD is free to play on and a penalty pass is awarded against the Yellow C.

The umpire restarts the game.