hmm, I'm not sure how or what can be done to get these kind of claims audited. The domain industry is not policed and therefore runs the risk of having people making claims about anything so long as two or more 'parties' agree to collude to do this and no one is the wiser.
For example, I could claim that I got paid $8.3m for a name (the 0.3m to make the figure look a little more 'credible') and unless there is a credible independent third party and accounting firm to legalise and verify such large sales, everything could be just smoke and mirrors and nobody will ever be wiser just because it was reported by some 'credible' source or some so-called credible domain players.
Benefit? The 'buyer' gets to say they paid $8.3m for my name and therefore future resale value should be equal to or more than this, and the 'seller' (me) gets to say I got $8.3m for one of my names, and therefore my portfolio which comprises similar names is worth $800m.
I'm not saying that this is the case here, but I find this aspect of the domain industry wide open to manipulation and Enron scams.