With the availability of Internet to disseminate information very rapidly, 'they' were paranoid about truth leaking out onto sites such as PPRuNe....
However, there are a few 'mates in confidence' rumours about the probable cause of at least 2 'unexplained' CFIT fatal accidents. One concerned a Hunter T7 near Shawbury in the early 1970s and the other a Tornado GR1A in Scotland in 1994....