I work in ASDA, and often on Scan and Go.
Our security are constantly watching the cctv and can see if a customer does not appear to be scanning every item, the member of staff on Scan and Go will be informed ( along with every other member of staff wearing a headset ) and given a description of the customer.
I then wait on the customer arriving at Scan and Go and will have adjusted the scanning handset to ' scan now ' so when people like your friend arrive she automatically gets a ' random ' check. ( and so will every other customer that arrives in Scan and Go ! )
If your friend had chosen to go through basket shop or trolly shop, she would still have the random check and my colleagues in that area are aware of her arrival as security will have kept us informed as to which section she is in and when she is approaching us.
The random check will be carried out by my colleague in basket shop or trolly shop, unless ' we ' are over staffed in which case I amy come and do it myself.
Security will confirm that I am scanning the correct customer's shopping.
After the scan is completed and the customer pays and leaves, I print out a duplicate receipt and fill in the ' security book ' with details of every item not scanned, and attach the receipt. A description of the customer is also written into the book, i.e. lady with 2 children, long brown hair, early 30's.
Usually it is one or two items that were not scanned, but sometimes it can be £200 worth in a £300 trolly worth of shopping - that is deliberate - no one makes that many ' mistakes '.
A couple of my full time colleagues are very good at recognising customers, and ' we ' will be told via the headsets ' the lady that failed her self scan last week by £200 has just returned to the shop ' .
' We ' can tell from looking at a trolly the rough amount that is spent, and can/will print out a receipt as the customer leaves and if the receipt shows £50 worth of shopping paid for and ' we ' believe/feel there is £200 worth of shopping in the trolly, ' we ' will let security know. And they will perform a random check of receipt before the customer leaves the shop.
Many customers have forgotten / not realised that when they signed up to Scan and Go, that they agreed a. the scanning is done by 18+ and b. that they may have a random check carried out. The agreement is also that c. the shopping will be rescanned by a Scan and Go colleague and they do not have the right to insist on taking their trolly to a staffed check out till instead.
Yes ' we ' often have customers throwing a strop re their shopping being scanned, and threaten to leave the full trolly with me - that's fine, you go to another supermarket and do another full shop. I don't care. You want to drive 10 mins away and trundle around another supermarket and fill your trolly all over again. Good. I will happily find a colleague to put back all your shopping, it will be done quicker than your next shop is done. I don't care.
I would much rather be sat on a be sat on a till serving my customers even if the queue is all the way down the aisle and there are only 2 staffed checkouts open, and I will be serving you with a smile and a ' hello '.
btw the police will not be called as no theft took place.