When God makes it rain inside Jerry's car, the shots of Jerry taken from Jerry's left side show his hair to be dry, but the shots taken from his right side show his hair to be soaking wet. These shots alternate several times, always with the same discrepancies.
The 1977 AMC Pacer station wagon that is used in this film does not have the optional front vent windows throughout it. In one scene in it where Jerry is pulled over by a policeman, the car now has small windows.
Near the end of the film when Jerry is driving away from the grocery store after being fired, he appears to be on a rural highway. When it cuts to a view of Jerry driving, the background is now an urban area with multiple storefronts.
The location of the shaving cream on Jerry's face while he is shaving changes as the shots change.
When Jerry comes inside after seeing the religious fanatics on the front lawn of his house, his wife Bobbie is waiting inside. The initial shots of Bobbie have her pigtails alternating between both being in front of her shoulders and the left one being behind her shoulders.
Back in the day when TV stations went off the air for the night, the first thing that they did was broadcast a test pattern and make a high-pitched sound. Eventually, these went away in favor of no test pattern and no high-pitched sound. When this happened, one's TV got what was called "snow" and a static sound. But when Jerry wakes up, his TV has the "snow" and the high-pitched sound. That "snow" should have been accompanied by the static sound instead of the high-pitched sound that it had.
When Jerry arrives to find religious fanatics on the front lawn of his house, the man with the signs is rotating them from back to front. In the next shot, he is rotating them from front to back. This is not a goof as the signs are all different sizes and have different messages; i.e., they are not sequential. The man can pull them out in any order that he wishes.
[at 1:09:58 into the film] God comments to Jerry that people speak so many languages that no one can understand each other (see Quotes), but according to the story of the Tower of Babel (Genesis 11:1-9), it was God who caused people to speak different languages so they would not have as much unity, but that does not make His statement here a goof. It is not.
When Jerry tells his wife Bobbie about the interview with God, she serves him a full bowl of chicken soup, which she sets on the table. When he sits the first time, the soup is there; then he gets up to pace and when he returns to the table, the bowl is gone. The next shot is over Jerry's shoulder and he eats three spoonfuls of the soup. The camera switches back to a front shot and the bowl is empty. Response: Jerry gets up and then sits down in a different chair. He then moves the bowl of soup in front of him. The bowl was not that full when it was first served and the later angles do not show the level of the soup.
[at 1:08:16 into the film] When Jerry is first shown in his hotel room, there is a telephone on the dresser. The Reverend Willie Williams had told him that there would be no outside calls whatsoever, but they forgot to remove the phone from the room. This is a hotel, so incoming and outgoing calls can be controlled at the switchboard downstairs. As a result, there would be no need to remove the phone from the room.
After the TV newscast about Jerry, a hand wearing a solid blue shirt places the telephone receiver on the cradle, which is covered by a dish towel. The next shot reveals that no one in the family is wearing a solid blue shirt. Since the phone was intentionally taken off the hook and the family is all in the living room, it is God that puts the receiver back on the cradle so that it will ring.
John Denver's flesh-colored half-body suit is visible when, as Jerry, he steps out of the shower to talk to God.
Near the end of the film as Jerry is walking out the back of the Food World grocery store after being fired, the Lucky Store letters on the top of the store can be seen to be facing in the opposite direction (i.e., the letters are backwards). Lucky is a supermarket chain in California.
Near the beginning when Jerry is driving down the road speaking to God on his car radio, the radio dial is in different frequency positions as the camera switches back and forth from Jerry to the radio. BH.
When Jerry opens the letter stating that God has granted him an interview, the word interview is spelled incorrectly (it is spelled as interveiw).
The trial for slander in this film would have been a civil trial and would have taken many months, if not many years, to come to trial after the alleged slander took place. Neither side would be permitted to call "surprise" witnesses at the trial. The witness list would have been made known to both sides well in advance of the trial as part of the discovery process, and each side would have had an opportunity to depose the other side's intended witnesses before the trial if they so desired.
When Jerry turns back to Mrs. Leven and Mrs. Green in the supermarket, a boom mic is visible near the mirror.
Near the beginning of the film, Jerry and Bobbie are getting ready for bed after having read God's initial note. Jerry blows his nose, crumples his tissue, throws it at the wastebasket, and misses. Bobbie mocks him saying, "Air ball!" In fact, it is not an air ball, as it bounced off the rim.