Audible to a Fake Punt.

at least twice during phins game when steelers were punting wheaton lines up wide left as a gunner and no dolphin
is on him. IMO it seems like we could easily get a 1st down if we audible to a snap and the punter throws a simple pass to wheaton literally no one on him. Even cbs color guy dan fouts pointed this out. Any reason why we don't do this? I honestly can't remember down distance will have to check tape but seems like an easy audible addition -- assuming that mcbriar can throw that far and do it quickly cause we are a man down on punt protection of weaton stays wide like that.
Are there any former punters out there and if so did you all ever have an true audible on a punt play if you got a certain look from the defense on a punt? Maybe too risky in the snow like that to do it. thoughts?