What I find unlikely is the comment that the Captain pulled back so hard he sheared the pins on his control column. I have always been taught on Boeings that you cannot apply excess force to the control column that can result in damage. If the controls are jammed due ice you can pull or push as hard as you physically can. If the Captain and copilot oppose each other there will eventually be a break out and then then the left elevator will follow the Captain’s input and the right elevator will reflect the copilot’s input. This happened on the Egypt Air 767 crash in the atlantic.