To be honest I was worried that Riley Dixon gave it away - he kept turning to the coaches before the hike. My husband and I looked at each other and he said "a definite fake, there is no holding play that he has to check with the coaches".
wouldn't be surprised if there isn't a check-off signal, depending on how the opposition lines up.
One of the most satisfying parts of that play was Groh predicting Nova would an all-out rush in that situation (I forget the term he kept using).