When Friday and Gannon go to investigate a possible burglar, the voiceover tells us that it is 9:28 PM. You even see Gannon pick up a flashlight before they go outside. However, when they go outside sunlight is still quite visible as everyone can see everything clearly and the flashlight is not even used. Due to the fact that the call interrupted the officers watching an NFL game shows that this should have been some point in the latter part of the year when it should have been pitch dark well before 9 PM.
When Gannon parks his car, it blocks the driveway. Later, when he and Friday cross the street, Gannon's car is parked forward, clear of the driveway. Later, the car is back across the driveway and he finds a ticket for it.
Friday and Gannon are watching a live NFL broadcast on a Friday. NFL games were not played on Fridays, in part so they would not conflict with high school games. In 1967, the Rams and 49ers faced each other on October 8th and November 5th, both on a Sunday.
When Gannon and Friday sit down at the dining room table, the room is lit by a chandelier. The shadow against the wall shows the entire chandelier, showing that the lighting actually is coming from offstage. If the chandelier lit the room, you would not see its entire shadow.
Bill Gannon gets a bit dramatic and upset over getting a parking ticket outside his own driveway, but all he has to do is go to the office and himself get it erased.
When Friday and Gannon leave the house at the end of the episode, lights are reflected in the window as they walk past.
When Friday pulls his gun after spotting the burglar, he holds it close to his body, inadvertently pointing the gun at Gannon. This violates a key gun element of gun safety.
Joe Friday isn't as conservative as appears to be: when he and his colleague sit down to watch TV, Gannon's shirt is opaque while Friday's is absolutely see-through and he's not even wearing a T-shirt underneath.
Kent McCord's officer acts like he doesn't know the show's 2 main cops but he just met them in the previous episode.