To 'Say Again': Craig Penrice didn't exactly give his evidence altruistically - he was paid handsomely for his time spent in the witness box.
To 'Barnwood': Not sure where you got your information from but the RAF did not ask the USAF to suspend their investigation. Indeed, I'm led to believe that the report to which you are referring was still in the USAF staffing chains and was never ready to be released during the CM timescale. I do agree, however, that the CM was hasty and should have at least waited until the BoI had reported its findings.
To anyone who cares to listen: The reason that a briefing was felt necessary was because of all the biased reporting on PPrune and the request for proper information from controllers. It is perfectly legal to discuss evidence which has been considered by a CM, and, even if it only gives food for thought to other controllers, then surely it can't be a bad thing? I think the intention was to arm people with the information lest they ever find themselves in a similar situation (lets hope no-one ever does).