I don't think so. The way I'm reading it, both fighters should be in a turn fight with the opponent closely following Boyd's rear at high speed.
In the case of a flat plane, you're dumping airspeed but you don't stall the aircraft. This guy explains it way better then I can, describing the maneuver as a Rudder Reversal: https://www.youtube.com/watch?v=5ab6Ek1UCcM. Skip to 2:07 to see him demonstrate it with model airplanes.
The Cobra you do enter into a stall (the airflow departs the top surface of the wings) and are instead relying on other some other aspect of the plane to control the aircraft and get the plane back into the fight.
Note that this is just what I know from superficial memory, I never studied it in depth.
