You should be fair when tipping a server
Carl is on a first date where their server is just out of training and messes up their dinner order.
Carl wants to show his date the kind of person he is when paying the bill.
Carl is sympathetic to the server's jitters and leaves a generous tip.
Carl leaves a small tip to show he doesn't tolerate poor performance.
His date excitedly makes plans for another date.
His date does not return his calls later in the week.