See post 74. Red's say less than 1%, which would be less than 100, not 6 or 7. On the one hand that's over 6 or 7 years, on the other the paperwork isn't that onerous, and he admits to the paper that they consiously omitted a background check in at least one "special" case, failed to report multiple handgun purchases, and discarded denials. Those are conscious acts, violations of the law, not sloppy paperwork.
It's worth noting that the alternative to gun dealers maintaining the paperwork is a government registry, which they'd be happy to maintain.
For many reasons, that I'd rather not go over, it looks more like a sloppy op. It looks like the background check box was not filled in, because the paperwork was set aside and forgotten, after the special order was made. When it eventually arrived, they probably overlooked it, and assumed it was done. That means he probably didn't have an organized ringbinder system, or the equivalent. I think the willful argument in fed court will focus on the warning given at the first audit, and his failure to clean up his act.