Visible crew/equipment: During Batman's interrogation of the Joker, when he picks him up and slams him against the wall, for a very brief moment you can see the camera and the cameraman in the reflection of the mirror on the right. (01:29:10)
Continuity mistake: When Trevor gets home from work and sits down in his lounge, between shots the sheets hanging over the chair he is sitting on change and items (such as a stack of books, newspaper, etc) suddenly appear on the radiator behind him. (00:03:15)
Continuity mistake: At breakfast, the morning after Maria has just arrived at her Uncle's house, the uncle calls Maria's father a coward. He has a glass of brown drink in his hand. He's just taken a drink and the glass is 3/4 full. Maria angrily refutes that her father was a hero and the glass, still in his hand, is now full to the brim. (00:19:20)
Visible crew/equipment: Near the beginning of the movie, Lucy and Susan run across the street and go into the subway. As they're crossing the street you can see the camera boom's reflection on the back of the black car. (00:09:25)
Continuity mistake: When Hancock puts Mary on the hospital bed after she's been shot, the blood on her shirt changes drastically from shot to shot.
Continuity mistake: When Hellboy has been speared in the chest and fallen to the ground, the POV shot of Nuala and Nuada has been turned so their heads are at the right hand side of the frame - from Hellboy's point of view their heads should be to the left.
Factual error: Near the beginning of the film, Calico is sitting with a cat on his right shoulder. Their reflection is shown in the glasses of a man directly opposite. The reflection shows Calico and the cat in the same position instead of being reversed, as a reflection would be. (00:04:30)