THE clock was ticking. I’d zipped round the supermarket, self-scanning as I went, and I now had about 15 minutes to exit, pack the car and get to work. But here was a security guard telling me everything would need to be scanned again. After unpacking the first bag, he lifted out an empty crisp packet. “Did you eat these while you were going round?” he asked. No, I replied, I was not eating crisps while shopping, and I had not shoplifted a packet of Walker’s Baked. He rummaged in the bag for a few other pieces of forgotten litter – old shopping lists and receipts – and offered them to me. “There’s a bin over there.” I stared at him. “You can put those right back where you found them,” I said. READ MORE: We work with refugees in Glasgow. The BBC film on our city had these glaring flaws Grumpily, he complied. It then transpired that in the process of re-scanning my entire weekly shop, he had somehow accidentally deleted the whole lot from the till, and from my app. The clock kept ticking. As I scanned it all again myself, I asked: “So what was it I missed?” He looked blank. “What was missing, when you checked the first 10 items?” “Oh, nothing. Sometimes we just have to do a full re-scan regardless.” Perhaps it was a coincidence that I had recently written in these pages about supermarkets displaying discounts the night before they come into effect – a clear breach of advertising rules – apparently to avoid having to pay workers for a night shift. Because of course I was neither a known thief nor an anonymous customer. Through my use of the self-scan app and loyalty scheme, the supermarket knows more about my tastes and