I didn't hear what the ref said over the microphone in the stadium, and haven't seen the television replay to see what the announcers were saying. Also, haven't seen a slo-mo replay. I haven't heard a definite answer.
Either way, it was a BS call that the official was saving in his back pocket for the perfect time to use it.
Next year, we should use the Pyramid Play from the 1930's. Who cares if we get a penalty.