When Miss Graveley visits the Captain, we see a case of nautical flags on the wall behind him, with a model ship perched on top. But in the final shot of the scene as Miss Gravely is leaving, the ship is gone.
In the second-to-last scene there is a large wet spot on Jennifer's blouse. A few seconds later, the wet spot is completely gone.
After viewing Sam's roadside paintings, the wealthy man's chauffeur gets into the passenger side of the car and slides over to the drivers side. The car is heard starting before he even reaches the driver's side.
In the first shot of the general store, the sign that reads "Gas and Oil" is perpendicular to the road. In the following shot of the roadside stand, the sign is parallel to the road and closer to the gas pump.
When the Captain and Miss Gravely are at Miss Rogers' home, the Captain is holding his shovel with the blade down. In a close-up, the blade is up by his face. Then later, it is down again.
The envelope the Captain takes out of the dead man's pocket, which is addressed to Harry, is not postmarked.
They keep burying Harry in close proximity to a large tree as they find the ground is easy to dig in. That close to a tree that size, on a Vermont hillside, that would have to withstand New England Winter winds, would be a maze of thick roots.
Sam's rectangular shovel is for snow, sand, etc. Not for digging graves or holes.
The word "Admittance" is misspelled on the Post Office sign in Wiggs Emporium. It reads: "No Addmitance P.O. Dept." This is intended to be a subtle joke.
After he draws Harry's feet, Sam puts the paper block under his left arm with the beginning of his sketch barely visible. (This might be caused by the lighting.) In the next shot as Sam is leaning over Harry's body, the charcoal on Sam's sketch is darker and more complete.
After Arnie discovers Harry's body in the bath tub, Harry's foot can be seen twitching just as the door opens for the second time.
After the hiker trips over Harry for the second time while reading his book, Harry can be seen breathing several times.
When Jennifer (Shirley MacLaine) accepts Sam's (John Forsythe) marriage proposal, a housefly can be seen to land on his left shoulder. As they kiss, the fly hops up and lands back down on his jacket.
Throughout the whole movie the audio\video is mismatched due to the fact that parts of it were filmed in a local gym due to bad weather.
After Arnie opens the door to find Harry in the bathtub he asks, "Hey, what's he doing in our bathtub?" Once the camera switches to a wide shot you can see but not hear Arnie repeating the end of the line.
They should not have put Harry's shoes back on. They should have gotten the shoes back into Deputy Sheriff Wigg's car.
When Sam and Jennifer are talking in Jennifer's house, the shadow of the boom mic can be seen moving across the top of the doorway behind Sam.