Did you enter that the initial $6k to the Traditional is nondeductible? That way, it is all considered basis. FMV at the end of the year is $0, because the entire distribution was converted, and it all was already taxed, and there are no earnings. And don't forget that Traditional, SEP and SIMPE IRAs are aggregated for purposes of determining pro rata taxable against basis.

Your taxpayer should have no tax; not even on half.