I'm sure you are.
Do you feel otherwise and, if so, why?
Let's just say that I'm not much impressed by the "multiple sources" in this story, nor with the fact that UPI were said to have "aquired documents" about early Hamas history (which seemed to be sort of irrelevant). Nor am I much impressed with the fact that ths story, such as it is, is to be found on no reputable news outlets but on scores of your (and Mr. Lied's) garden variety nazi, holocoust-denial and history revisionist sites, something that usually means that something is very, very rotten.
But hey, I'll go track down the life history of Sale guy. And Cordesman. Nothing like making sure :)).