All QB's in this system have the leeway to call their own audibles, whether it be for changing the play, or to adjust the pass protection scheme.
Even Everett Golson made some audibles in 2012, when he was pretty green. Zaire also made a few, Kizer made many a good call, and Book was one of the best at calling them on the fly.
Pyne was no different, that he could have called his own audibles at the line.
He generally didn't, though. Instead, he'd do the "scan" and wait until there were 15 seconds left on the clock, and look over to see if Rees wanted to change the play. That got us more than a handful of delay of game penalties.
It became pretty clear to opposing DC's, that he was entirely dependent on Tommy Rees when it came to play calling, which is why a lot of times, the opposing defense got the jump on the snap, since there was barely any time left on all too many occasions. Even the top notch offensive lines (and ours became a pretty darn good one halfway through the season) in football will be at a disadvantage if the defense knows exactly when the QB will snap the ball. If this were a video game, it would be the equivalent of John Madden Football, where the player on defense could hit a button just before the player on offense hit the button to snap the ball, and often times, the QB or RB would get dumped for a loss.
It's no surprise that most of our best offense came when we snapped the ball with at least 5 seconds left on the play clock.