I'm going to speculate on the events that transpired here.

1. Boss screws up scheduling, forgot that other employee 'C' asked for the night off two months prior.

2. Two months pass, and it's time for 'C' to leave (you know, because they properly requested the time off beforehand)

3. Boss panics because he's comfortable in bed watching LA Law and doesn't feel like leaving the house to cover for employee 'C'. He then remembers that since he's the boss, he can turn to one of his subordinates to cover the graveyard shift (that no one wants to get stuck with anyway.

4. Boss calls the author and must be convinced that he has to get his comfortable ass out of bed and go do the job that he expects his subordinates to do.