When Matty is in the restaurant with her husband and Ned, the wine that is poured is white but the husband is drinking red.
After he and Matty have sex for the last time, Edmund rolls over to his side of the bed covered in sweat and hair matted to his forehead. Seconds later when he hears noises downstairs, he springs from the bed completely dry with no indications of his prior activity.
Peter is at the diner with Ned and Oscar and buys two glasses of iced tea. The amount of tea in the second glass changes between shots.
Ned gets visit in jail and his hair is noticeably darker than earlier scenes.
When Ned and Matty are arguing in the entry way, the ceiling fan behind Matty changes speeds between shots.
When Ned receives the yearbook from Wheaton, Illinois, the postmark is from Marina del Rey, California.
Package Ned receives while in jail containing Matty's high school yearbook is addressed to Florida State Penitentiary, Tallahassee, Fl. Whereas the state pen is actually located nearly 150 miles east of Tallahassee at Raiford, Florida. Meanwhile, the Florida Department of Corrections headquarters is indeed located at Tallahassee.
Just before Ned and Matty have sex the first time, Ned left her, returned to his car and then came back to the house finding Matty waiting and lusting for him inside the house. Finding the door locked, Ned destroys the front window to get into the house to get at Matty. It would seem that Edmund Walker would ask Matty or the housekeeper what happened to the window but he never inquires about why it was destroyed. Not a goof: the viewer has no idea what conversation might have taken place.
At Teddy's place, when he is showing Ned how to rig the arson device, he offers to set and rig the device for him as thanks for Ned helping him get out of prison. Ned accepts Teddy's offer, saying "Thanks". But then later Teddy doesn't set or rig the device, Ned does. Not a goof: Ned shakes his head and then says, "Thanks," as in "thanks for offering, but no."
Fog depicted in some scenes, is unheard of along the South Florida coast in summertime.
At the end of the movie, as Ned thumbs through the yearbook, the way he flips through the pages is wrong. He looks at "Tyler" first, then flips the page forward for "Simpson". Since "S" comes before "T", he should have flipped the pages backwards to see the "Simpson" photo.
When Matty and Edmund are in bed before Ned gets there, the sheets are white with gray stripes. When Edmund goes for the gun after hearing a noise downstairs the sheets are now a light tan color.
Teddy showing how to set up device, stops to turn music down, and later, on top of bunk bed, turns music back up. Neither area has audio/radio. Music amp located in far corner of room.
Characters at outdoor concert fan themselves (presumably to show how hot it is), even though there is obviously a heavy breeze that would make such activity superfluous.
Doesn't anybody in this town have air-conditioning? It's obvious that heat is a leitmotif here, starting with the title, and that passion is rampant, but there seems to be a copious amount of sweating, even indoors, in what's supposed to be a relatively affluent community.
When Heather is picked up after her stay at Matty's house, the boom operator is reflected on the car.
The shadow of the crew is visible on the pier when Ned is running in the morning.
Just before seeing the clown driving a car, Ned Racine walks into reflected sunlight. This light causes the camera and crew to cast a large and distinct moving shadow on the road next to his convertible.
Peter Lowenstein states he doesn't want to be an assistant county prosecutor forever. Florida does not have county prosecutors. His title there would be assistant state's attorney.