Character mistake: When Howard's men bail the guy out who was with Bobby Saint at the arms deal, they are beating him up in Saint's club. Howard Saint (John Travolta) shoots the man responsible for not watching his son. The man fall down to his knees and then says the name John instead of Howard.
Character mistake: Jenna has Sparkle letters at her work. Wouldn't she get caught earlier?
Character mistake: The pilot announces that they will be flying from the 310 (California) to the 212 (New York City/Manhattan). There is no airport in Manhattan. The closest airports are JFK International and LaGuardia which are both in area code 718 (Queens).
Character mistake: Flynn has been reading for a while, taking notes, spreading books around, etc. - when Nicole arrives and says that it was nice to watch take-off from the cockpit. The plane must have been in the air for a long time by then.
Character mistake: During the scene when Jesus is being whipped, the devil is walking through the crowd looking at him, in this scene only Jesus should've been able to see him, however look closely and one of the characters in the crowd's eyes can be seen following him.
Character mistake: The final deciding question at the Law Society quiz is "what was Madonna's first UK single?" Bridget says it was "Lucky Star" but the quizmaster says that is wrong. Rebecca says it was "Holiday" and the quizmaster says that is right and announces that her team have won. The only problem is that "Holiday" was not Madonna's first UK single either, her first UK single was "Everybody", released in December 1982.
Character mistake: When Marie joins Bourne in the bathroom while he's getting medicine, Marie says he's burning up. She gets a washcloth, wets it and dabs Bourne's neck. She only had what couldn't have any more than a tablespoon of water and dabbled it less than a few seconds. It couldn't have had any effect on someone who was burning up.
Character mistake: When Marco is trying to raise his rifle to assassinate Senator Arthur, he held it upside down with his scope below and turned over in the same scene, He is an expert marksman.
Character mistake: Tom Manning criticises Hellboy for using a lighter, (correctly) telling him to use a wooden match instead. But he then lights a match and immediately puts it to the cigar, instead of waiting for the sulphur to burn off and using a pure wood-fuelled flame to light it. He's not as well informed as he thinks.
Character mistake: Jill states that a 5 kiloton nuclear weapon will sanitise the city, however, such a yield is far too small to destroy the city. (00:42:00)
Character mistake: Garfield calls two different dogs Boomer. The first is a white dog at the vet. The second is in the scene at the train station when the dogs from the pound come in Garfield calls Spanky, the brown dog, Boomer.