Continuity mistake: When Charlotte hastily makes the bed and shoves Ted out onto the window ledge, the bed covers rearrange themselves between shots: a purple sheet that she'd tucked in before is now peeking out over the bedspread. (00:15:05)
Continuity mistake: While wounded D'Arnot hides in the tree, a leaf on the left swaps from laying on his shoulder or hidden behind his head, between shots.
Continuity mistake: The social worker takes "the brother" to stay for a while at a female friend's place. Her son, "little Earl" has a bandage on his left knee. He peels the bandage off and sets it on the floor to show "the brother alien" his injury. A medium shot shows there is no bandage on the floor. The "alien" puts his hand on the boy's knee, and heals it. The very next shot the bandage is back on the boy's knee and the scene continues.
Continuity mistake: During the Grand National, the leading horse unseats its rider at the third fence (jockey with pink and black spots), but just a few minutes later the same horse and jockey combination are back up with the pace.
Factual error: Throughout the entire movie, the SBD Dauntlesses they are working on have the national insignia with the red ball in the center. This was discontinued in May 1942.
Character mistake: The ref says there's no rules before McClure fights Whiplash but she tries stopping them later.
Continuity mistake: When the coach instructs the guys telling them that their 'pistols don't shoot blanks', the clipboard under his armpit flips around at the cut. (00:06:00)
Other mistake: When they're walking on the Tri System, you can see the wrinkles in the fabric used to create the foggy background.