WAMU’s Diane Rehm wasn’t behind the microphone for her regular 2-hour Friday slot of The Diane Rehm Show today, because she was reportedly injured in one of those bizarre accidents that seem like only happen on TV sitcoms. Filling in for the host, Susan Page of USA Today reported that Rehm was running across the street on Thursday when her heel got caught in the leg of her pants. As a result, Rehm tripped,…