The original BOI didn't have time to interview the eyewitnesses as the Court Martial proceedings halted the inquiry. Once the BOI was reconvened, the original board members were used, with the exception of the President due to Op Telic.
As a result of all of the publicity, they were keenly aware of the sensitivities and did all they could to find doubt in a fellow air trafficker's actions, whilst remaining utterly professional and impartial to the best of their ability. The written report is the result of a lot of soul searching, hard work and anguish. It should not be written off as a white wash and an agenda to lay blame at one person's door.