Once again, I am going to give the same advice that I often give in these situations....STOP using the self checkout lanes...at ANY store. The potential for mistakes exists and stores, instead of giving people the option to correct their mistakes make a whole lot more money on civil demands.
What is going to happen is that she is going to get a civil demand from Walmart to pay them several hundred dollars.
I am particularly adamant about this issue THIS WEEK...because my 80 year old mother, who has plenty of money, who has never committed even a traffic infraction in her life let alone anything else, made the mistake of attempting the self checkout lane because the store was very crowded, and the lanes were long. She messed it up completely and she called me to help her and the idiot LPO who was dealing with it wouldn't budge.
She is devastated...to her this is the worst thing that has ever happened in her life. To me, this was an idiot LPO...working for an idiot company.