An Airplane should snap to the left with the power on and enough elevator. If you are dropping the right wing, I have little doubt that it is one of three things.
1. The right wing has a positive incidence compared to the left. (You will see this by the amount of right aileron trim you needed)
1. A bowed fuselage or built in right rudder causing way too much right yaw, or more likely
2 Too much right engine thrust.

Get rid of your right engine thrust and you will almost certainly get rid of your right wing stalling before your left wing causing this snap.

You would need a huge difference in elevator travel to cause that kind of snap. On full scale aerobat only one side of the elevator is trimmed and it doesn't cause the plane to snap any differently.