Giving a S$1000 note to buy a 45 cents mineral water at an express counter

All right. This issue may be right or wrong to some people. But the story goes like this. I was queuing up at an express counter at a supermarket in Orchard Rd. In front of me was a fine lady purchasing a bottle of mineral water. What made me noticed was, "How come she is taking a long time?" Then I found out that she passed the cashier a piece of SGD$1000. Apparently, the cashier did ask her whether she had small change or not. I was thinking as well as showing a lame look at her, "How the hell an express counter have big change when they handle a few items per customer?" Even if she wanted to change the note, she can go to the other counters which had not much people. As a result, it forced everyone behind the express counter to accumulate with more people and made more people waiting behind. The cashier got no choice, but to cancel her item and called the manager to pass the change, so as to proceed on with other customers. I felt that this is ridiculous...