You're assuming Mike Parker told Eileen what Philip told him. That's faulty because you're assuming he told her and that Philip told him. Philip isn't known for trusting many people and the way he dropped Mike when his divorce came through doesn't speak to me of much faith in Mike. He rarely, if ever, spoke to Mike ever again before his death, so I don't think they were as close as some like to believe.
I have never said I fully believe Philip has been faithful. I've pointed out (and no one has been able to deny) that none of Eileen's comments can be proven with irrefutable evidence. You can believe her but you cannot state she has credibility when no one has ever been able to prove anything on Philip (though I myself would be amazed if he's been completely faithful). Credibility has nothing to do with how many people believe you. It depends on whether you can back up your statements with evidence. Therefore, she lacks credibility.
James Hewitt makes all sorts of claims, but half of them can't be proven, so he lacks credibility. James WHittaker lost his credibility when he printed something about Charles and Diana that was not only impossible to prove, but was proven untrue. Mohammed al Fayed makes claims that are impossible to prove, no matter how much money he spends trying to prove them, so he's lost his rather shaky credibility anyways.
