The film shows Bellevue High's quarterback completing several passes in the win over De La Salle. In the real game Bellevue did not attempt a single pass the entire game.
De La Salle's loss to Bellevue High took place in a night game at the NFL's Seahawks home stadium, then-named Qwest Field, not a high school stadium as depicted in the film.
De La Salle played, and defeated, Long Beach Poly in October 2001 not in 2004.
The doctor comes in and tells the Coach that he had an 83% blockage of his PLA, calling it the "widowmaker" and required 5 stents. The "widowmaker" is actually a blockage of the left main artery or the upper LAD artery. The PLA is so small also that it would not accommodate 5 stents.
De la Salle defeated Long Beach Poly 29-15 in 2001 and 28-7 in 2002. According to what I could find, they did not play again for over 10 years which means they could not have played in 2004. In the movie, De la Salle is playing LB Poly in the afternoon at Veterans Stadium in Long Beach. Varsity HS football in Long Beach is generally played on Friday nights.
(at around 1h 35 mins) The Stanford letterhead shows a misspelled date for January. The date shown is "11 Januaray 2004".