It's mean to be rude on purpose.
Derek is sitting waiting for his food at a diner when he sees the waitress walk by.
Derek wants to stop the waitress.
Derek stops the waitress and asks her how long before his food will be out.
Derek sticks out his foot and trips the waitress, making her fall to the floor.
The manager realizes Derek's food has been taking a while and brings it out himself.
The manager of the diner makes Derek leave and tells him to never come back.