On numerous occasions he has dumped on the idea of dumping his prep work and game plan for the week and calling things not on the play sheet when the offense is in a funk.
He has commented on this when failing to adjust to give Tackles help with chips on pass protection.
He has sheepishly admitted that he HAD to call plays they did not plan on during game situations they did not plan for. Specifically, recall the lack of a 2 point play versus the Cardinals because his one 2 point play he liked required 3 receivers and Janis was hurt.
Running an offense without the plan would be foolish indeed. With his talent advantage, he would be an idiot not to try to impose their will on other teams. However, there are times when your plan doesn't work and you must dump it. If you have fallen well behind (think Panthers in 2015) you need to do it before the 4th quarter.
This is a very admirable trait taken to an extreme.