Distraught Employee
While she tried to prevent the tears from falling, she did not succeed. She returned to the back with this check. After seeing Courtney in such a state, the boss assumed that a bad thing just happened.
Was It A Mistake?
Could it be an error? Perhaps he did not notice how much money he left and assumed that the bill was higher than it was. Maybe he wanted to leave her $10 and not $100! Still, it did not sound likely.