Shop lifting, even at point of sale, does not occur inside the cash register. To that end you would be monitoring the customer, which can include employees on the customer side of the transaction.
As a customer, I’ve simply been given the wrong change and been told that I paid with a $10 and not a $20. Most of the time I take their word for it, but once I was actually paying attention and had a manager come over and count down the til.
True. Granted, the marketing material that I saw was 20+ years ago, and the recording was still done with videotape. One product would superimpose a text feed of the register tape on the video, so they were recorded simultaneously.
But money-skimming does. I know someone who got fired for that... After being caught on camera.