Those basic facts are quite well known, and the destruction of the USAF T3a fleet was very controversial within the aviation community.
With regard to an engine stoppage causing a stall/spin - that should not happen with a trained (or even solo student) pilot; the link is not there without a reasonable degree of mishandling. I've flown a short assessment on the M260 and personally saw nothing that would cause that immediate link of engine failure = stall = spin. The aircraft did not show a large pitch change with power, nor a strong tendency to spin from a level or turning flight stall; I doubt that it would have been certified by UK CAA if it had.
Do bare in mind that single engine piston aircraft are all potentially subject to engine failures and that all pilots flying them are trained to deal with engine failures - it's a very substantial part of initial and recurrent training.
I don't deny that there may well have been some problem with the USAF T3as, but I don't believe that it's reasonable to say that any incidence of vapour locking led to spinning accidents, the link doesn't really make sense. That said, in the UK fleet, I believe that the T67 has the highest rate of stall/spin related fatal accidents, per flying hour, of the training fleet - however virtually all of those fatalities were in the smaller engined T67a and T67b models, not in the more powerful military variants which are also operating in the UK civil and military training environments.
G