Corrected entry: There is no reason for Lucifer to grant John a wish. The devil is neither a nice guy nor a Jinn, and he already got what was "in the pot." Of course Constantine was very helpful to him (commiting suicide to signal the devil that his son is revolting against him), but the devil for sure would just take "the gift", only sarcastically saying "thank you." Realistically it would end with twin-sister Isabel staying in hell and maybe John going to heaven because his suicide rescued Angela from getting stabbed by Gabriel and threw back Mammon in hell, a godly sacrifice.
Corrected entry: As Lucifer comes down to John his feet are covered in a black, tarry substance that drips all over the floor. When he walks into the hydrotherapy room the tops of his feet are still covered in this substance. But in the shot where he pulls Angela away from Gabriel, his feet are clean. (01:43:40)
Corrected entry: When Angela sets off to "rescue" Constantine, she makes a point of working the action on her handgun, thus putting a round in the chamber and cocking back the hammer. She then immediately holsters the gun without lowering the hammer. I cringed when I saw this in the movie - it's an extremely reckless move as only the gun's safety (of dubious reliability) is keeping that gun from accidentally firing. I can't imagine even a rookie cop, let alone a seasoned detective, doing something so dangerous. (01:10:05)
Corrected entry: When Lucifer and John are talking, after John cuts his wrists, Lucifer says something about cutting too deep and the tendons being sliced, therefore making the finger movement not so good. Yet later in the scene John is holding the cigarette in his hand freely, as if there was no trouble with his fingers holding it.
Corrected entry: In the scene where Keanu Reeves is killing the first demon, he lights a cigarette before entering the room, he then proceeds to place it on the desk (where it is seen often for some artistic flare) but when he puts it on the desk its not a cigarette, it is a cigar, or loosely rolled "blunt" which is why it is burning so slowly. (00:04:35)
Corrected entry: In the scene where Constantine explains that there's a different Bible in Hell, he says that it gives a different picture of Revelations. The name of the book is Revelation (without the 's'). It's a common mistake, but someone as well-versed in demonology as Constantine should know the correct name.
Corrected entry: Towards the end of the movie, when Angela is shooting the Mexican in the pool, you plainly see that the bullets are exiting out his back through his very white shirt. You see the blood burst forth from his back as they exit, then you see them hit the wall behind him. Yet, just as he grabs Angela and shoves her underwater, you have a perfect view of the back of his now completely unmarred white shirt - no holes whatsoever anywhere.
Corrected entry: When Angela is watching a video of her twin sister's suicide, made by security camera, take a close look at the final scene when Isabel is standing on the edge. She is standing still, but the camera view moves to put the girl in the center of the screen, then stops. It doesn't seem like regular movement of rotating security cameras (they wouldn't stop), and it doesn't look like movement of motion tracking cameras either (they'd be continually moving tracking Isabel). This scene was obviously filmed to provide for a certain artistic impression rather than show accurate security camera footage. (00:25:00)
Corrected entry: In the first exorcism scene, John burns the girl with a symbol. A couple of shots later, the burn mark has moved.
Corrected entry: In the scene where Keanu walks into the building of the first exorcism he lit up a cigarette. The next shot shows it was burned down, and then the next shot when he walks into the bedroom its a full cigarette again.
Corrected entry: Near the end, Gabriel is holding John's gun asking her to kill him. A split second later, he's holding it in a different manner.