Doonesbury by Garry Trudeau for December 24, 1973
Nixon: Ted, Mr. Smith here is working for the special prosecutor. He'd like to hear the tape of last April 9. Aide: Yessir, Mr. President! Nixon: We'll have it for you in a minute, Mr. Smith. As you know, I and my staff are eager to help the special prosecutor's office in any way we can! Well, Ted? Aide: Gosh, Mr. President! As luck would have it, both recording were out being repaired that day! Nixon: Holy smokes! What a coincidence!