421dog
Again, if you refer to Colgan, review their training in the Bombardier.
At shaker the drill is to add power and maintain altitude, not at Stall.
Recovery from shaker is a different animal from Stall recovery, Renslow appears to have mistaken his attitude because of the a/p loss just prior to shaker. If he was (incorrectly) holding altitude, after all the a/p had been , (but with diminishing a/s) He may have mistaken 'a/p' means 'level'.
He may not have remembered his neglect of adding power at low pitch.
In any case, I don't see that this pilot didn't follow at least his advanced training re: shaker. He may have just not been aware of his noseup attitude. That probably led to Stall, and the need to immediately abandon his trained in shaker recovery and revert to Stall recovery. For whatever reason, it appears he didn't make the connection. Should Colgan train power and nose down at shaker? ?