There are some errors in the stats for two games on the 2003 Cardinals relating to the pass attempts by Josh McCown and Jeff Blake. They must have been changed some time (some years even) after the game and are reflected in the nfl.com gamelogs and gamebooks.

Game 1 - 11/23/2003 vs. Rams
PFR has Blake as attempting 28 passes. It should be 27, with McCown playing and going 0/1

Game 2 - 11/30/2003 at Bears
PFR has Blake as attempting 31 passes and 1 for McCown. It should be 32 for Blake, none for McCown, who is listed as "Did Not Play". PFR has McCown with 10 GP and 3 GS in 2003. It should be 8 GP and 3 GS, as he did not play in this Bears game and I'm not sure what the 10th game PFR has him listed for. The only 8 games he played in are the 8 he threw at least one pass in, which means the 11/23 Rams game and not the 11/30 Bears game.

Summary - gamelogs need changed for the number of attempts from Blake and McCown 11/23 and 11/30 games. McCown needs his games played stats changed to 8 for the 2003 season.

Sources:
http://www.nfl.com/player/joshmccown/2505076/gamelogs?season=2003
http://www.nfl.com/player/jeffblake/2499676/gamelogs?season=2003
http://www.nfl.com/gamecenter/2003112305/2003/REG12/rams@cardinals/
http://www.nfl.com/gamecenter/2003113000/2003/REG13/cardinals@bears
Arizona Republic article from 11/24/03 confirms McCown threw 1 pass in the 11/23 Rams game