"Any idea on how I would go about it being coded incorrectly? Wouldn't that be an easy way to get audited?"
A claim that a Form 1099-R is incorrect is done by filing a substitute Form 1099-R (Form 4852) with an explanation and indeed is likely to result in an IRS examiner review the filing since the IRS Automated Underreporter System will almost certainly flag the tax return for examination and it would be up to the examiner to determine whether or not to accept your position. That's why I indicated that I have no idea if this approach would be viable. However, the law simply says that a return of contribution before the due date of the tax return be accompanied by any gain or loss attributable to the amount being returned, and it is mathematically possible to determine an allocation that satisfies that requirement and would have resulted in a distribution of the amount actually distributed. (Unless there was no investment gain or loss while the money was in the account, the amount returned will not be the same as the amount distributed and you would still have some excess contribution if there was a gain or some amount of regular distribution if there was a loss.)
