I, too, cannot find the BBC interview, which is both frustrating and strange (unless the whole thing has been made up by Kemp, of course). Latest interview I could find was on Hard Talk about Syria.
That aside, the main issue according to Kemp (same article as the OP, but further down) was this:
"Lord Richards was talking about the ongoing legal campaign against British troops who have fought in Iraq and Afghanistan ...
1,492 cases of alleged abuse in Iraq are under investigation, and over 600 in Afghanistan. Most of these cases involve allegations against multiple servicemen, so the number of troops under scrutiny can be counted in the thousands. We are not talking here about minor misdemeanours but the most serious forms of abuse including rape, torture and, in Iraq alone, 235 accusations of unlawful killing.
Some soldiers have been under constant investigation for more than 10 years. Some have been acquitted during preliminary investigations or at court martial, only to be dragged back to face repeated legal inquiries and judicial hearings. In some cases, there have been as many as five investigations into a single incident."
Shouldn't the first response to the serious charge (in effect Whitehall's complicity in malicious prosecution) made by a former Chief of the Defence Staff be to ask: Did the interview take place? Has Kemp reported it accurately? Are Lord Richards' "facts" correct?
The contention of the OP has been sneeringly dismissed by several without any attempt to examine the facts.