One thing I learned from TE Rob Gronkowski is that the Patriots not only film watched themselves, the other team, but also the Refs.
Watching the Refs in the playoffs so far, for big moments, or moments you know are big before the play like Steelers just had a 4th down...
Refs seem to be staying extremely quiet, no flags thrown, just letting whatever happens, happens. The Refs seem to be trying to keep a low profile. That's something they need to plan for.