Sometimes coaches will tip off the broadcast crew on some trick plays they might run. They won't tell them when they will run them just to look for a certain formation or something like that. Maybe a seemingly innocent gesture that no one would pick up as a clue but the coach let the broadcaster know if he does a "certain something" look out.
Same thing goes with officials. They meet with the coaches before the game and a coach might alert them how they might do an onside kick or trick play and to look for it - again using a seemingly innocent gesture to tip them off.
I did it once when I coached Youth Baseball. I knew the home plate umpire well enough to trust him. I was coaching 3rd base and told him if he heard the word "Hero" coming from me we were going to try and steal home within the next few pitches. I told him our batter was going to take every pitch until a strike was called and as soon as a strike was called on the next pitch we would try and steal home. Now he is aware of it and more importantly would be focused on the pitcher because I knew when we did it the pitcher would commit a balk and sure enough that is what happened. We needed a run and I told the batter "All we need is a hit - don't try and be a hero." The batter had to tap home plate to confirm he got the signal to take the next pitch and we were stealing home. The pitcher was in the windup position and my runner on 3rd got a decent lead and I told the team as soon as the pitcher puts the ball in the glove to head home knowing unless the pitcher stepped off the back of the rubber it was a balk. I knew the pitcher would instead not step off and take the ball out of his glove and come forward to home to try and throw out our runner. Our runner was out by a mile but the pitcher clearly balked - the umpire called it and we got the run - and the opposing coach was furious at me for doing it but I didn't care cuz we got a badly needed run.
So officials/broadcasters are tipped off by coaches
10 of 11 defensive players playing AT or in front of the 1st down line. I have no idea what made Saban think he could RUN for a first down with this facing his team. I have no problem with him going for it but if he is gonna go for it leave Tua and the offense on the field. They stood an infinite times better chance of making it than this did
FWIW I can't even count the number of times a team will come out of a timeout and the (losing) coach will tell me what they are going to try and do to make sure I know and can react accordingly. It helps them out because now instead of blowing my whistle for a foul I know they are trying to commit I will give them a chance to do what the coach said they would try and do.......then call a foul if they can't.