I'm not sure how many high intensity "you're stealing!" confrontations really occur.
The other issue I have is that the barcode scanners are not activated until the weight sensor settles out, which can take several seconds up to a minute, so it's way slower than going to a checker. If the weight sensor didn't gate barcode scanner activation I would have a much better experience.
All they really need to do is verify the weight of the total transaction and have the associate check on any discrepancies. And they can probably use a very noisy weight signal with a low-pass filter. They don't need to blow a ton of money on an AI solution that is about the same level of inconvenient.
If I had 10 or 20 million dollars I'd build a better self-checkout.
It's so much nicer of an experience compared to machines that just stop functioning until an employee can "help" you.