Actually I cut and pasted from My website!!
Ejection seats
The Mk 12 seat is a tad more adanced than the Mk 10 and I'm led to believe that the system of parachute deployment is similar to the US Navy NACES seat.
In all of the videos (there are 3 versions or views doing the rounds) the PSP does not have a chance to auto deploy and I doubt the pilot had the time to manually release the PSP. He is under the canopy for less than 4 seconds.
BUT
I stand to be corrected!!!