Watch the scene where Eddie Murphy gets his hair cut. In the end of the scene Arsenio Hall leans down into the mirror with his earring on his left ear. The next scene in the nightclub the earring is on his right ear. It's not because the barber scene was shot in a mirror either.
Actually, that scene was shot in the mirror. If you look at their jackets you can see their "I Love New York" pins are backwards. The earring was on the same ear the whole time.