There is an excellent explanation of the USAF Firefly incidents here:
http://www.cessnawarbirds.com/articles/index.html (The Wichita Mescalero & York Firefly)
Having flown, aeroe'd and spun a T67M I can say it is a superb aeroplane but it does need the correct spin recovery technique. Mis-apply the spin recovery and it won't come out.
I have no comment to make on the accident itself.