If it's too hard to detect, management doesn't have much choice.
It would be smarter for that feature to require a manager's key, and then the manager could actively monitor the situation. But since the manager can't implement that feature, they have to work with what they have.
It read like they DID know how to spot it, and the reaction was... "never again for anyone under any circumstances".
Blanket bans like the one described are always wrong. ;)
If there's a problem, monitor it after every shift, or every day, or weekly. You know who worked what registers; monitor/scan/review, then take action against the offenders.
I worked food service with POS; we had to review things every drawer change, and discrepancies were noted. Repeated discrepancies (either money or between food usage and money) would be tied to someone (or multiple people) and action was taken. It's not always that hard, just a bit time consuming, but... it's part of the job (or was for me).
Solving personnel problems with policy is unfortunately common at companies in the small-medium space. Very small companies tend to be more person oriented, and very large companies tend to have outgrown it (though they may still do it at the department level).
It is also one of the most annoying mistakes I see frequently repeated at startups and young businesses.
Solving problems with policy is common in all companies. It’s programming at the organisation level. Every policy is either a good candidate for automation or an indication of automation limitations.
It would be smarter for that feature to require a manager's key, and then the manager could actively monitor the situation. But since the manager can't implement that feature, they have to work with what they have.