Like many accidents, when unwound, there is a change of fortune, a slip, or a missed item. Forgetting the increased ref speed, Renslow was settled with expectations that went missing in a flash. The shaker dislodged his plan, he thought he had ample speed (he did), the reversion gifted him with an a/c trimmed for maintaining altitude with low power, a nose up and increasing. I think he reacted correctly to the shaker, as he was trained to do. The rising nose rose even faster as he 'held altitude', then applied power, raising the nose even more, I think he didn't know his AoA, he'd have seen the blue below the line, and pushed. One additional miss in scan, perhaps. Besides, he was 'straight and level', except he'd forgotten to advance power with condition. When the pusher tried to pull on his back pressure, he resisted, was he trying not to bust a checkride?