I did the Hunter OCU early in 1960. The spinning exercise in the T7 had been removed from the programme because during an earlier spinning flight the aircraft would not recover. The crew initiated the ejection sequence, the canopy detached, but one of the seats wouldn't go. As the pilot prepared to clamber over the side, he noticed that the spin had stopped. He flew the aircraft home, and his seat was discovered to have some mis-rigged cables which would have stopped the parachute from opening. Sabotage was suspected, but couldn't be proven.
I don't remember if the successful ejection and become a successful parachute descent.