Bingowings said:

Posts of that kind, while I understand where they are coming from are pretty pointless.

If someone strongly disbelieves that David has cancer they will not donate, end of story.

On trust those who have donated and not asked for a refund believe Dave's story on trust.

Those who develop strong doubts will ask for a refund (and if they don't get one that's a separate if not related issue).

Unless Dave tells us otherwise or compelling evidence to the contrary is given those who trust Dave on this issue will continue to do so.

Which means for them David has cancer and needs funds quickly.

David needs compelling documentation not to prove his innocence or guilt but to successfully raise the money he needs, not just from readers here but from other organisations as well.

The main focus for David is to get better.

To do that he needs money.

To get the money he needs swiftly enough to be effective he needs appropriate documentation.

Exactly.

If you believe him, cool.

If not, that's cool too - drop the subject, move on.