Just over half of Amazon Fresh stores are equipped with Just Walk Out. The technology allows customers to skip checkout altogether by scanning a QR code when they enter the store. Though it seemed completely automated, Just Walk Out relied on more than 1,000 people in India watching and labeling videos to ensure accurate checkouts. The cashiers were simply moved off-site, and they watched you as you shopped.
I mean, they test it a lot. It seems like the general philosophy though was that the ways of fooling the system reliably are somewhat convoluted, so if someone is willing to do all that, just let them lol.
Amusingly, one of the particular vulnerabilities that they mentioned having problems with in the UK in particular was people just brazenly going into a store, taking down some cameras or other equipment (networking equipment, edge compute, etc.) and Just Walking Out.