Continuity mistake: Carrie's height changes constantly.
Factual error: The Royal Canadian Mounted Police officer who phones Jesperson to tell him he has not been accepted is a colonel. In common with most Canadian police forces, the RCMP uses British-style civilian police ranks (inspector, superintendent, etc), not military-style ranks as the American police do.
Continuity mistake: Kevin Shepherd pulls over in front of her fiancee's dad. It's still a wide angle, but you can see distinctly both her and his left arm stretched forward; she is looking at her engagement ring, he has his hand on the steering wheel. Before the camera cuts away though, he lowers his arm; it is not acknowledged in the new shot, where both have still their left arm forward. (00:03:35)
Factual error: Roland enters the train to go to the war, in 1914, with "Spanish Flu", but that was the (wrong) name given to the 1918 flu pandemic, which lasted from spring 1918 through spring or early summer 1919.
Other mistake: The protagonist (along with other warriors at the beginning of the movie) sports a mohawk-like style with perfectly buzz-cut sides, and he keeps this impeccable, modern day 'do even when he ends up being a crack addict in China.
Continuity mistake: The glass that was dropped and shattered on the floor had a different pattern of fragments when Mitch [Robin Williams] knelt to clean it up. Most obvious was that the majority of shattered pieces settled toward Mitch's feet but were on the opposite side of the largest piece of glass during clean-up. There's also a "stupidity" in the way Mitch wiped up the glass - pressing down on the thin towel (apparently to entrap fragments), which is most likely to result in getting pierced. (00:01:40)
Continuity mistake: Rich is dangling a light bulb above his dad's head. When the camera shifts to a close-up of Rich, the light bulb is higher - almost across from his own face - but back to dangling above his dad's head with the next camera shift. This is independent of Rich's dad telling him to "hold the light steady." (00:06:23)
Continuity mistake: Sam stretches his arm across the table to set a drink about an arm's length away from Ernest, but the side view shows the drink in front of Ernest. Sam's chair is also closer and angled toward him. (00:29:08)
Factual error: In a classroom scene, Mia takes her phone out and checks Instagram. It can be seen that she is on the network "Koodo" - a Canadian mobile operator. The movie takes place in Portland, but is filmed in Vancouver. (01:00:10)
Continuity mistake: After David hits Hugh he gets a wound on his mouth which gets smaller the next day.