Very possible in the design for a need to pull the pin backwards after re-setting the hammer to the 1/2 bent position - Due to the angles involved when rotating the breech with only your thumb or hand, the pin could drag heavily in the primer's cup until retracted, or simply move out of the pin's depression as in some of the other earlier actions. I can visualize the enlarged pin assisting in grabbing it for retraction if necessary - as it seemed to be.