If the rule was technically violated, I'll take back what I said about firing the guy. But it's still bush league.
If it's a rule that's getting abused and not being called, you don't pick the playoffs to suddenly start calling it. It's like when the NCAA started actually calling hand checks in basketball. They didn't wait until the Final Four and have a ref start calling it out of the blue. They let the schools know it was going to be a point of emphasis and they started calling it early in the season to allow teams to adjust.
To single out a team (any team, it just happens to be Dallas in this instance) to suddenly enforce the rule against in a playoff game is idiotic.