During the last game he slides into the endzone and when he stops the centre of his body is clearly on a border of green field and grey field. But when the shot changes to a different camera he is nowhere close to any green field.
The movie is supposed to be in Washington D.C. Washington doesn't have a football stadium. The Washington Redskins play in Landover, MD. So the movie was filmed in Baltimore, MD. They used Camden Yards, Orioles stadium, and the stadium where the Ravens play.