During the beginning of the Championship, a soaking wet #23 (Doug Savant) is dramatically fouled. The coach then yells for a time out. Standing next to the assistant is none other than #23 with hair completely dry, complaining about the same foul that just injured him. The very next clip is #23 laying on floor, then he is helped to the bench.
On the way to the party when Stiles is surfing on top of the
van, they pass the same "Jack in the Box" twice.
When Scott comes out of the locker room for the big game and
talks to his coach, his face is dry. However, when he gets in the huddle, his face is obviously sweaty as if he's been playing, when in fact he's hasn't entered the game yet.
The day after Scott learns he is a wolf, Pamela notices that "something is different about him". Scott closes his locker, but when Boof talks to him a few seconds later, the locker is open again.
After Scott makes his big entrance for the championship game, he is seen throwing his gym bag on the floor twice.
In the game against the Cadets (first game in which Scott turns into the wolf), Scott is fouled right after the opening tip-off. As this was not a shooting foul or the 6th foul committed by the Cadets, Scott would not have been awarded any free throws.
During the basketball montages when Scott becomes the wolf, the cheerleaders are clearly a couple of yards on the court during the plays. This would never be allowed.
In the opening game Scott hustled for the ball and growls before taking a shot shown in slow motion over the music Chariots of Fire. Had the shot gone in, the Beavers still would have lost the game by a lot.
Coming out of the shower, Scott's underwear is visible under his towel.
In the showers after the game when the wolf passes behind the lockers, as soon he gets into the shower you can see his bare shoulder and an obvious wolf mask instead of an elaborated makeup.
During the Surfing USA montage, during the sequence of back flips, if you look closely you can see a pair of handles on the roof of the van for the stuntman to hold onto. The most obvious angle is during the last back flip.
In close up, the transition from Michael J Fox's face to his partial makeup is very visible. Even in his full face mask loose latex is visible on his lips.
During the big game, the coach says to a player, "That's a purple heart, kid." By watching his mouth, it's clear that he is simply chewing bubble gum, and not talking.
The line "On top of everything else, there was a full moon last night" by Scott clearly dubbed in as he turns around.
When Stiles says to Scott, "It's looking good out there, babe" and Scott replies "Yeah, how would you know Stiles?" You can clearly see Stiles's voice is dubbed.
While Stiles is van surfing, a police motorcycle escort with its hazard lights on is briefly visible in the bottom left of the frame.
Camera dolly tracks visible reflected in the shop windows.
Crew visible in trophy case when Scott bangs on the door after leaving the dance.
When Scott turned into a wolf and was riding/dancing on the top of the truck a support wire is clearly visible when he is doing a handstand.
There are no palm trees in Nebraska.
It's November, according to the calendar in the coach's office. The green trees and summerlike weather are not plausible for Nebraska at that time of year.
Pamela says: "Wolves aren't supposed to be shy!" Wolves are actually very shy around humans.
At the end of the scene where Boof is playing basketball with Scott's father, Boof leaves and Harold proceeds to play on his own. After his final shot he celebrates with both fists in the air, however his shot clearly hits the rim and bounces out.