X selects goods in a supermarket and takes them to the cash desk. The price is £185, but the cash register records only £85, being incapable of recording over £100. X pays £85, knowing it is not the true price, and removes the goods. The manager of the supermarket is supervising at the cash desk.
Although normally it is the intention of the parties in this type of case that the property shall not pass until the price is paid (the £185), the property here passes to X upon payment of £85, because the manager intended the property so to pass.