Please excuse VVS :-)
P.S. it is worth pointing out the other gripe which I have not videoed...
At the check-out, you scan the check-out barcode. From a user interface point of view I think that at that point it should transfer control to the check-out in all cases. It knows you are at the check-out, and which one. You should be done with the handset then.
There are two issues.
1. It asks a question on the handset at that point - regarding items that did not scan. Why? Why not ask that on the check-out as the first question. This annoying split of a question on handset then next question on check-out is not helpful.
2. If you are picked for a random check, you are told on the handset. The check-out transfer does not happen. At this point there is NO ALERT to staff of an issue - the status Red/Amber/Green on check-out is not set to alert staff. Nothing tells staff you are stuck and you have to find someone or wait indefinitely for someone. If the transfer was to checkout at that point, and then it says "random check" that would allow the check-out status to alert staff. The re-scan could use the handset or the check-out reader, does not really matter.
I just feel that this is not thought out well at all.