In reply to ATrainspotter: Your summary of the situation is too simplistic, too black and white. In reality, the issue is about establishing credibility. Once a certain climber has this, they can, and are trusted to tell the truth. That's how it works.
Credibility is established, often by accident (i.e. by just going climbing and being seen climbing well by a variety of climbers, but critically those who are experienced enough to understand what is actually occurring), but more typically by design (i.e. by producing filmed ascents, or photos of ascents where the photographer - who also has to have a base of credibility - vouches for the fact that the photo was not staged. That being said, most photos are completely staged.)
So, not every ascent needs to be filmed or witnessed, just a certain amount.
For example, I've seen John Gaskins on Walk Away sds. He didn't climb the full problem in front of me, but I saw enough of a display of disgusting power and finger strength to realise that he had done it. I've also seen him boulder on a number of other occasions, and he has been filmed doing a very hard traverse at Woodwell. Moreover I know other climbers (e.g Greg Chapman, Neil Kershaw) who's judgement I respect, who can vouch for his awesome ability from first hand experience.
So if John told me he'd just done a new V15 tommorrow, I would believe him, even if there was no film , or no witnesses.
Ultimately I believe it is the responsibility of the high profile climber (sponsored or not) to establish their own credibility. If they don't want to play that game, then they shouldn't bother reporting their ascents, and they certainly shouldn't try to support themselves financially through related sponsorship, however meagre the sums of money might be.