The left gauge on the oxygen tanks indicates 10 psi when the doctor examines it, yet it indicates 2 psi before and after his verification.
When Perry and Della first pull up and park at the Davenport real estate office, Perry sloppily parks his car at a poor angle with the left front tire across the line into the next closest parking spot.
When the secretary and police officer pull up and park later, Perry's vehicle is parked in the parking spot perfectly within the line markers.
When Perry and Della explore Davenport's office, the dialog indicates it's nighttime. But all the outside parking lot scenes are obviously shot in daylight.
When the "Doctor" is being questioned by Perry. The camera cuts to the Judge, he is leaning forward with his hands on the bench. The camera goes back to Perry, then a quick cut back to the Judge. He is then leaning back in his chair with a hand on his chin.
Ed Davenport pulls up to a cabin in a motor court and walks right in. Despite the fact that he has not checked in, the door has been left unlocked.
In Perry's office, early on, the real Louise refers to Myrna as Louise, just after she says, "Well, there's something that I haven't mentioned..."
Dr. Renault says he gave Davenport "chloramine". Chloramine is a disinfectant used to treat drinking water. It also can cause/aggravate respiratory problems; not a wise treatment for someone in an oxygen tent who is having problems breathing.