When Andy enters Mr. Izamoto's Judo studio, a Judo student in a gray sweatsuit (a young, uncredited Kent McCord) is leaning against the divider wall several feet in from the entry as Andy approaches Mr. Izamoto. Although he is shown beginning to stand up straight in the first shot, when they cut immediately to a side shot of Andy and Mr. Izamoto, the Judo student has now disappeared.
After Barney issues the ticket to Fred (Allan Melvin), Fred tells Barney that when he sees him out of uniform he's going to beat him "to a pulp" and grabs the knot of Barney's tie and pulls it up slightly with his right hand. Barney then delivers a line about being careful about how he talks to an Officer of the Law and Fred is still holding the knot. The next cut shows Fred's right hand off Barney and putting the ticket into his pocket.
As Barney is writing out a ticket to Fred (Allan Melvin) for littering, he looks across the street at what is presumed to be a public clock on a building and states that it was 12 o'clock. Barney then looks back at his citation book to write down the time. There are no clocks on any of the buildings in Mayberry.
When Andy sends Barney to confront Fred (Allan Melvin), he says there was a light on at the grocery. No light was on.
When Fred (Allan Melvin) leaves the courthouse after paying his fine, the pedestal for the studio lights or some other studio equipment is clearly visible just outside the door.
When Fred (Allan Melvin) encounters Judo instructor Mr. Izamoto, who is dressed as and pretending to be Barney, Fred watches him walk towards him from down the street. Although short in stature like Barney, Mr. Izamoto's build does not resemble Barney's build at all. Barney's build is extremely lean and Mr. Izamoto's build is very muscular. In addition to this, his walk is entirely different from Barney's very distinctive "swagger." When they are fighting, Fred has the opportunity to look directly at Mr. Izamoto and although it is supposed to be dark in the alley, there is clearly enough light to see that this is not Barney.