Expert Card Technique: Close-Up Table Magic by Jean Hugard and Frederick Braue Page 322
Personal Comment: Let's be honest here. The effect is nothing of great importance or impact. But it is a cute interlude. Because the plot makes it interesting. Succeeding, then falsely assuming failure is pretty much the opposite of the usual "magician in trouble plot" so it will be experienced in a very nice way. It is a nice little throw away filler. Really nice.