Why did TurboTax deduct my QCD from the income side, but still included these deductions in the itemized deduction total?

TurboTax correctly deducted my $10,000 QCD from the taxable amount of my IRA withdrawal, but included this $10,000 as an itemized deduction and used the itemized deduction option rather than the standard deduction because it was larger.  This has lowered my federal tax, but I think it is a mistake because these contributions have been counted twice.