'Most F4 aircrew were told that spins in the F4 were unrecoverable and to eject whenever entering a spin, especially the dreaded flat spin. I have no knowledge of an RAF F4 ever coming out of a spin by using the drag chute'
Absolutely not: a) we were never so instructed as the F4 had a very good spin recovery outcome (except for the unrecoverable flat spin) and b) most of the spins recovered were via use of the chute as this was part of the standard spin recovery technique. The drill was to reduce AOA whilst centralising ailerons and rudder, throttles to MIL power range, then deploy the chute, extend the RAT and then if still out of control, stick fully forward and full in-spin aileron.