The tires on Mathews' police car when he talked to unit 1410 were very dusty, yet he had not been driving on the dusty dirt road at that point. In the subsequent scene where he is responding to Loring Road they were clean. The scene was filmed out of order.
Sirens are used to warn other traffic. The use of sirens on vacant fire roads was useless and only served to let the criminals know the location of the police vehicles.
Unlike the jewelry store robbery, no explosion or interior scenes were shown for either the market or department store robberies. In each of those, the robbers were seen entering and then leaving carrying a grocery or shopping bag. Only a sound effect was used for the explosion, and no one at the department store reacted to the explosion, as shoppers were shown exiting the store in a normal manner. It appears the actors entered the stores, made purchases, and left with no one inside the stores aware of the production.
Even though it had been shown and used on numerous occasions, the Highway Patrol helicopter was not mentioned or used in the search for the suspects in the canyon even though it would have been ideal for that purpose.
Nelson complains to Herrick that he has to use inferior parts to build the bombs, and Herrick responds by saying that if he used proper parts, the police could trace the bombs right back to him. However, neither of them seems to be concerned about leaving numerous fingerprints all over the bomb components and containers.
Mathews on the phone asks the parole officer about Bert Nelson and listens for a period of time, apparently being given information. Sgt. Williams walks in and asks about the investigation and Nelson. Mathews says to check him and fails to mention the information he received over the phone.
Sgt. Williams comments that they have partial fingerprints from the bombs that were too smudged for comparison to records, but the partial prints could be matched if they developed a suspect. Since fingerprinting suspects is the process for print records, a live suspect could provide no more detail than their fingerprints already on file.
One of the robbers mentions seeing the police car behind them on Loring, yet they had turned off Garfield onto Loring with no police car in sight, and at that point no police car had been shown behind them on Loring.