Yes. The article mentions various “fraud detection” schemes in place (weight etc) but I don’t get why random checks aren’t just used instead, or in addition?

I once left cash on a machine and sat with store security while they went back through the video to see what happened to it. (They were happy to give me the money after seeing someone quickly pocket it before the attendant noticed)

If they wanted to cross-check, the videos see everything - but obviously it's not cost effective.

In England you can't search people just because you want to.

It’s not a search of a person’s things after leaving the checkout. It’s a manual audit taking place with a random probability. You aren’t being “searched” because the transaction isn’t completed yet. In the traditional checkout people are asksed to put their not yet purchased items on a conveyor too. I’m sure you agree that’s not “searching” them.

Note: in most places such as grocery stores, customers scan items while picking them using a handheld scanner while putting things in their cart. Then you just pay for the total at the checkout, at which point the register could randomly decide to give you an audit. If you don’t agree to ever being subjected to that, your only choice is to use traditional checkout.

In other places (perhaps most notably IKEA) items are self-scanned at checkout time.