Continuity mistake: At the end of the movie when Evan and God are talking under a tree in a field, God is holding a wooden staff. As the camera cuts back and forth between Evan and God, God's hand changes position from holding the top of the staff like a cane to holding the staff further down like a walking stick.
Continuity mistake: During the flood, if you look at the clothes of the people on the ark, they are completely dry, despite several waves crashing over the boat, soaking them.
Continuity mistake: When Evan and his family are standing on the ark just before the flood, Dylan's watch shows a completely different time than one of the spectator's watches - neither of which around 'midday' (noon) when the flood is supposed to happen.
Continuity mistake: In the first part of the movie, Evan is driving his new Humvee and several birds fly over and poop on the windshield. Of course he turns on the wipers and it streaks all over the place. When he is done, there are still obvious and large streaks on the drivers side yet during the next 10 scenes, the streaks appear and dis-appear several times.Most obvious when he parks and walks past the front of the vehicle.
Factual error: Where exactly does Evan park? Members of Congress have access to underground parking facilities at the House and Senate office buildings which are located directly adjacent to but not at the Capitol building itself. Evan appears to park on the street, in front of the Capitol building, in a parking space that would ordinarily be blocked off for security reasons.
Factual error: As the story goes, two of each animal are to board the ark, one male and one female, side-by-side. Thus, two pairs of peafowls(one pair of each species) should board. Yet, in the scene where all the birds are in Evan's office, we see two peacocks(male) of the same species side-by-side, when we should see a peacock and a peahen.
Factual error: When the news reporters are summarizing the events of September 22, the camera pans back and up looking over Capitol Hill towards the Northwest. The sun is casting a shadow towards the west indicating that is morning though the "flood" was at midday. Also the rainbow indicates that the sun is behind the viewer and to the East. The westward shadow also casts a bit southward indicating the a shadow of an early morning in the summer. With it being September 22nd, the shadow would cast directly west since the sun rises due East during the equinoxes. (01:25:30)
Plot hole: When everyone is passing the bill and Evan's suit changes to the robe, how is it that no one noticed that he came in wearing normal clothing and then his clothes changed into the robe in less than a second. Heck it showed his family watching him walk right into the room wearing normal clothing, and then watched him the entire time. How did they not notice that he never once changed his clothes?
Visible crew/equipment: In the building scene when the animals are watching, you can see a trainer leading a dog at the side of the screen.
Continuity mistake: When Evan tries and fails to shave, you can see him using the same razor every time, but there is no hair on the razor or in the sink.