Eh - sounds like a relatively simple issue to address.
When you use a regular checkout at a store today you have to check your receipt to avoid being ripped off. Items ring up at the wrong price or as the wrong item all the time. If you don’t verify your receipt you are at throwing money away. So you would still have to do the same thing with this system.
We always do. 100 percent of the time, the discrepancy is in the store's favor. We go back to the checkout and complain to get our money back. Real strange how the "mistakes" are in the store's favor. Almost the same thing for take-out/drive-through restaurants; almost always overcharges or missing food items are in the restaurants favor. We always double-check before leaving.