Nearby stores within the Ralph's and Albertson's chains avoid this issue by simply forcing the shopper to close out the order before proceeding to payment, according to a California TV station's report. The Safeway stores had a "finish" button but was it not required that it be hit before proceeding to payment. One wonders how much time was spent watching and fixing these holes and creating and distributing the signs, as well as dealing with customers who were apparently paying for other shoppers. It's also possible that many of those ripped-off shoppers never detected it, but they will now that media coverage has kicked in. How will those shoppers feel about Safeway's "let the glitch happen and we'll fix the individuals who notice later" approach? Compare all that to how much time it would have likely taken IT to simply force that the "finish" button be hit before payment was accepted? Ahhh, the wacky world of retail cost-benefit and analysis.
The self-checkout software at a Safeway chain in California, Vons, lets the shopper move directly to the payment area and then still buy more items. This bit of flexibility likely seemed a good idea at the time, until it was discovered that it meant that the next shopper could scan groceries and those groceries would be charged to the payment card of the first shopper.