Yea, that does sound like breaking problem. I have no clue how to begin solving that one.
I feel like there was an idea, not in this article, where people would scan items as they add them to their cart and then this walkout process was really just a redundant verification of walking out with the purchase. Still, that does sound like a lot of error prone noise.
Yea, i think your video surveillance case has a lot of value. With AI Algorithms these days and the postive feedback loop being clearly a purchase, it would be weird not to have this.