It's rather unclear what Dalton means here. The interpretation that seems likeliest to me is that Dalton can easily provide independent evidence to a professional auditor (i.e., someone who can be given trusted access to sensitive data, and someone who isn't easily induced to lie on a client's behalf) that the tally is correct.
Unless it becomes routine to actually employ these auditors, that doesn't really answer jtokoph's worry.
Postscript - Indeed, that's what he meant: on http://daltoncaldwell.com/we-did-it he says "In the very near future I will ask an impartial 3rd party take a look at our data (while preserving all privacy of our backers) and publicly verify that the join.app.net was operated in an honest manner."