Lots of comments ... but nothing here about the fallacy of chasing points.
Unless I have done my math incorrectly, both squads scored 4 TDs and kicked one FG. Without the chasing of points, game would be tied 31 to 31 after last Chiefs score, unless Andy Reid decided to go for 2 for "the win" after their last TD, a very unlikely decision at home. Chiefs went for 2 because at 30 to 29, the XP nearly literally was meaningless.
McDermott chased points too early in the game, repeating the mistake that was a substantial benefit to the Bills just a week ago.