“If you are satisfied so that you are sure that there was an imitation firearm in the possession of the people who carried out the robbery, then if you are satisfied so that you are sure that anybody who was involved in the joint enterprise in count 1 knew that an imitation firearm was being used in the robbery, then that person can also be guilty of count 2 wherever that person was, providing the person is part of the joint enterprise in count 1 and knew that there was an imitation firearm being used, if you are satisfied so you are sure that one was being used, then that person can, in fact would, be guilty of count 2, but it is a matter for you.”