Ask Texas Longhorns head coach Mack Brown for a highly specific take on a game in the direct aftermath and he'll probably differ the question, wanting to take a look at the film first.
It's essentially the same for writers -- jotting down a few overall impressions with some specific recollections of important plays or moments, then it's time to get busy with the in-depth film study to notice defensive fronts and alignments, the performances of specific members of the offensive line, evaluate missed opportunities by the quarterbacks, etc.
For college football programs, the film is sliced, diced, and processed while the game goes on, allowing coaches the ability to evaluate tendencies and sort through the data on the most micro levels in the moments after the game is completed.
SB Nation Studios had a chance to go inside the Nebraska video department for a close-up look on how it all goes down.
Changing The Game: How Video Technology Evolved Football (via sbnation)
It's pretty awesome overall, but it even features Bo Pelini acting like a normal person. Or as normal as you can look when you have your t-shirt tucked into your basketball shorts. Enough to make a rage-induced accident seem like a decent look.
But seriously, this is cool stuff.