Revealing mistake: If you watch Herb's wife Patty drink her hot chocolate, it is very easy to see that the cup is empty.
Miracle (2004)
1 revealing mistake - chronological order
Directed by: Gavin O'Connor
Starring: Kurt Russell, Patricia Clarkson, Noah Emmerich, Nathan West
Factual error: There indeed was a moment in the game (vs. USSR) where Jim Craig was shaken up, but contrary to what's shown in the movie, the hit did not happen as the Soviets scored a goal. Furthermore, if a goalie is that flagrantly knocked down and out so that a teammate can get a shot off, it should be a two-minute penalty for "goaltender interference" and the goal disallowed.
Herb Brooks: Tonight, WE are the greatest hockey team in the world.
Trivia: If you listen very carefully to the part where Al MIchaels says, "Do you believe in miracles? YES...", you'll notice that it's from the original broadcast of the game in 1980. All other play-by-play was re-done by Michaels as the movie was produced. The reason they used the original 1980 broadcast for just that specific moment is that Michaels had a difficult time recreating the emotion and excitement he felt when shouting it as it really happened.
Answer: Since they all came from different, sometimes rival, universities, and thus had no commonality, he wanted to give them someone to dislike together, instead of fighting with one another. If they could all bond over what a bastard Brooks was, they'd come together faster as a team and have a chance of winning.