If your shopping cart is less than $100 then yes, the shipping details will display N/A for DC. However, if your cart is over $100 (i.e. the threshold where UPS charges for insurance), then the shipping details will display a price for DC even when “None” is selected for DC in the control panel (the price displayed is the cost of insurance, even though it is labeled DC). And yes, I would agree with you: Send values (ie insurance) should have nothing to do with DC, but the cost of insurance does get added into the DC value (for orders over $100) when “send values” is selected.
Please retest with your shopping cart over $100 and let me know if you can replicate this issue.