Whether you want to call it "trained" or "know", the man knows or is trained how to prevent a stall from occurring and knows (or is trained) on how to recover from a stall. In a "Q" or a C-152, what ever. He did not make it as far as he did in his career by not knowing "the emergency procedures to prevent the aircraft from stalling". Why he did not implement his training is another issue, but the training had taken place and he had demonstrated his ability as a PIC to recover from and/or prevent a stall.