If you saw the end of the Bears - Colts game last weekend, the Bears score with 2:01 on the clock to cut their deficit to five. They decide to kick deep. In that situation, the coach has to, absolutely has to, tell the kick returner to run the ball out if they kick it in the end zone. Because you want the clock to start and run a few seconds so that the two minute warning comes before your first down play.
Instead, the Bears kick it into the end zone and the Colts call for a fair catch.
It ended up not mattering because the Colts got a first down and ran out the clock. But that's the kind of thing that if the Bears had gotten a stop and got the ball back with an extra 40 seconds on the clock because you were too dumb to tell your guy that he had to return the kick, well, decisions like that get guys fired.