A pub opens a Biergartens in the summer months (a Biergartens is an open-air space where beers and food are served. It is often temporary and associated with a specific event)

 

• Clients must pay cash as its difficult to organize other payment methods.
• Each waiter has a bill pad and writes the orders of the customers.
• Each bill pad has 50 pre-numbered bills.
• When customers are ready to leave, the waiter calculates the price to pay and collects the payment.
• The waiter puts the money in a cash register and invoices on a holder spike near the cash register.

 

New Control implemented by the manager:

• The manager noted the sequences of pre-numbered bills assigned to each waiter.
• At the end of the day, the manager gatherers the bill that is on the holder spike puts the numerical order and checks their sequences

Required:

What is the risk that the manager tries to mitigate?

What is the assertation that the manager has in mind here?