Two primitive fishermen with spears step through the water and wait for the sand to resettle and for the water to become clear again. They're looking for flatfish.
A rainbow fish appears instead and one of the two doesn't want that fish touched. What's the most effective method of preventing it being caught?
I'd say it would be to accidentally on purpose muddy the waters and then the fish can't be seen. Not only that, it would now be tipped off and may well swim away out of range.
Maybe it's not the greatest analogy but you'll soon see where this is going. Maybe, as
Lucia Flecha da Lima claimed:
"Paul Burrell was perfectly capable of imitating Princess Diana's handwriting."
Maybe so. Maybe not. A whole host of thoughts crowd into the mind, to be filtered through predispositions and prejudices and please don't claim you're unbiased or looking only at the facts. You might be trying to do that and so am I but we're restricted by our experiences, by our foreknowledge.
This woman won't accept that Diana felt that she was going to be killed. It doesn't gel with her experience. There are obviously those who would place great store on da Lima being "one of the princess's closest confidantes" and therefore this being an appeal to authoritativeness, in order to conclude the letter's a fake.
But we don't actually know.
On the other hand, if it is true, then very powerful personages wish it to be the accepted view that the letter's a fake. It's only logical that no stone will be left unturned. Against that, it's only one letter and only one peron rejecting it, long after the fact. To appeal to numbers who believe in it or not is pointless.
Hand in hand with this is the necessity to vilify the opponent and the standard subterfuge is to label anyone accepting the letter as a conspiracy theorist. End of story. No need to pursue it further.
Against that, there is the view that a certain type of researcher always leans towards the conspiratorial explanation and this clouds his judgement when it comes to something which can be explained away more plausibly, by less sensational means.
This is serial rationality and the rationalist always has the advantage over the passionate ferret in that he appears ... well ... rational. A prime example is Cheney who always sounds plausible, even though he's not saying anything which stands the test. He draws on a few stock phrases which appeal to the no-nonsense conservative and that's accepted as truth.
On the other hand, the rationalist could well be right. I've read some quite cogent arguments for the "single bullet theory" with JFK, now that the hysteria's died away. The claim to "likelihood", witnesses' testimony and the relatively clear view from the building behind JFK, let alone the grassy knoll, is powerful but it might, after all, be wrong.
To claim Oswald couldn't have made it down those steps and be drinking a coke is a straw man, as is the ludicrous diagram of relative body positions in the limo, used to disprove the single bullet theory. And the vehemence with which both sides stick to their entrenched positions precludes debate. Actually, I believe it was an ordered hit but that's neither here nor there.
So, this letter. It exists. It's Exhibit A. To not admit it as evidence, you'd have to prove Burrell could have forged it so well it got past the handwriting experts. And who's to say Burrell forged it anyway?
Finally, the murky muddying of entrenched interests who'll either pay or kill. Well, what can one do about them?
Does it matter? I think it does. If it's a forgery - why was it done? And who did it? Burrell, to revenge himself on the slights he felt by the princess and the boys? Maybe.
One thing I do know though is that the "water-muddiers", the flat deniers, the "everything must be a conspiracy" advocates - none of them have any place in this process of finding the most likely scenario.
Most likely scenario because I don't think anyone's going to uncover the truth.