Further to previous discussions on the Brit SAS there is a book out now which shines a light on to workings of the SAS:

Special Force: The Untold Story of 22nd Special Air Service Regiment (SAS) : by Alastair MacKenzie

amazon.com

amazon.co.uk

I will quote two passages:

"Now, as I say, the soldiers [in the SAS] are the best you will ever meet. Nonetheless, within your troops too you have got men who will lie in their teeth, who will deliberately falsify accounts in order to make money for themselves, who will seduce their comrades' wives while they are overseas, whi will steal and who will even carry out armed robbery, and in case you think I am exaggerating all those things have been done by soldiers of this regiment in the last two years. Nor should you be surprised. You don't train tigers and expect them to sing like canaries and those men are highly individual and highly active." - Briefing to Troop Commanders by the Commanding Officer on 11 November 1975
and

As the myth of the SAS regiment has grown, it has become an increasingly introspective organisation, beset by the contradictions between its past and present values and by bad feelings within its ranks. Regimental officers have seen their authority undermined by the potent working-class ethos of their soldiers.

...

This book identifies that the utilisation of the special troops has not been at an appropriate political or military level. The strategic use of this exceedingly small, elite group of specialists has been based more upon the personal drive of relatively low-level officers than upon national necessity.
Note: my comments above were made before obtaining a copy of this book.