I lost some bottles of spirits on these.....
Scanned them through early so they were waaay out at the end of the collection area while I was still picking stuff out of the trolley. Plenty of people walking by the ends of the checkouts. Hard to concentrate on the machine and keep an eye out. When I got to the packing stage......you guessed it - they were no longer there.
I notified the management when it occurred a second time as I realised then that I hadn't just forgotten to pack them.
Now I used manned tills where I can eyeball the goods!!