(at around 46 mins) The morning after Bruce enhances Grace's breasts, he squirts ketchup on his toast. When the camera switches back to him as he gets up, there is no ketchup on the toast.
The hood of Bruce's car is alternately damaged and undamaged between shots.
(at around 39 mins) Seconds before the monkey comes out of the hood's butt, the hood on his left (viewer's left) with the blue jacket has a thin mustache and a small soul patch on his chin. After the monkey has come out, he has a full goatee when saying Bruce is 'El Diablo'.
(at around 10 mins) After the meeting, in the hallway outside of Jack's office, when Bruce is saying to Jack "I'm starting to get desperate man", his hands "jump" from open to close position between the cut scene.
(at around 10 mins) When Bruce is "playing jazz" for Evan, his thumb switches from being tucked when we are looking at Bruce, to extended when we are looking towards Evan.
(at around 1h 14 mins) When the Sabres win the Stanley Cup, it is just after 6 P.M. Championship games are almost always played at night for ratings. Furthermore, when Bruce leaves the TV station before asking for God's help, it is just before 7 P.M. The Stanley Cup Playoffs usually take place in May and June, but it is dark outside already. It would not start getting dark until after 8 P.M. in June.
(at around 1h 14 mins) The Stanley Cup prop looks nothing like the real Stanley Cup.
(at around 1h 4 mins) Grace is prompted to drive to the party when the dog throws her the car keys. However, the key is a Ford key, and her vehicle is a Chevy Blazer.
(at around 34 mins) When Bruce is in the diner, you can see the strings attached to the sugar and creamer when they move into his hands.
(at around 1h 18 mins) Flipped Shot: Bruce's Hair is parted on his left. When he meets God during the the town riots, his hair is parted on the other side for a split second.
(at around 43 mins) When Bruce puts both feet on the railing to "pull in" the moon, the background around him shifts from side to side.
(at around 38 mins) When Bruce licks his finger and touches his hip, smoke comes out of his hip, but the smoke isn't reflected in the window next to him.
(at around 1h 1 min) When Bruce is typing answers to the prayer emails, the contents of the prayers do not match the subject lines. For example, one prayer that has "RE: New Car" in the subject line is actually a request to find a lost cat.
(at around 36 mins) When God is explaining the rules to Bruce after getting Gods power, God tells Bruce there's only two rules he has to follow. 1. That he can't tell people that he's God. 2. He's not allowed to interfere with free will. Later in the movie (at around 53 mins), when Evan is doing a news report, Bruce is intentionally making Evan say and do things against his own free will which is clearly a violation of rule two, but God doesn't come in and do anything about it.
(at around 23 mins) In the DVD/VHS/Blu-ray/TV version, the pager shows the fictitious 555 number, made to avoid privacy issues, yet we hear Bruce reading the original number.
(at around 55 mins) When Tony Bennett is singing at the "Blue Palm" restaurant, the piano player's fingers and bass player are clearly not in time with the music.
(at around 6 mins) When Bruce looks at himself in the mirror, Sam enters the room to pee on the couch. The shot changes to Bruce, then back to Sam. On the right side of the screen, you can see the hand of the dog trainer, pointing to where the dog should be looking.
(at around 1h 26 mins) When Bruce is drenched in the rain, his microphone is clearly visible beneath his blue shirt.
(at around 33 mins) When Bruce Nolan plays Clint Eastwood and a shot is fired from nowhere, he is shocked and parks the car in front a diner. Right when he (Bruce Nolan) parks his car and before he sees himself in the rear view mirror, in the side shot, there is a middle aged man standing near the pole wearing a hat, shirt and shorts, clearly a camera man.
(at around 36 mins) When Bruce and God are standing on the water, you can clearly see the platform Morgan Freeman is standing on.
(at around 15 mins) When Bruce is sent to Niagara Falls to report, he starts by saying that he is reporting from Niagara Falls, New York. The view is obviously from the Canadian side of the Falls.
(at around 42 mins) Before Bruce "edits" the night sky, many stars can be seen. In downtown Buffalo, it is rare to see any stars at all.
(at around 7 mins) Grace talks about the AB+ blood type as if it's rare and high in demand. In reality, AB+ is the least in demand because it can only be received by other people with AB+ blood, and AB+ people can accept any other blood type. O- is the most in demand because it can be donated to any other blood type.
(at around 1h 13 mins) The word "prophecy" (the noun) is misspelled in the newscast headline, which reads, "Doomsday Prophesy" (the verb).
(at around 1h 14 mins) In the Stanley Cup, it is announced that the Sabres have "won their first championship in 22 years." In reality, this would have been their first championship ever, since the Sabres have never won the Stanley Cup. They made the Stanley Cup Finals twice: once in 1975 and again in 1999, but lost to the Philadelphia Flyers and Dallas Stars respectively.
(at around 3 mins) In the beginning when they are measuring Buffalo's biggest cookie, the tape measure is clearly not measuring the middle (diameter) of the cookie. The measurement would only be accurate by the diameter size.
(at around 24 mins) When Bruce is explaining to his dog where he should pee, he repeats, "House, bathroom, bathroom, house" and points to the house when he says house and to the outdoors when he says bathroom. In one shot, though, he points to the house and says bathroom and the outdoors and says house.