This goof is in reference to the design of the Wilsons' house. Throughout the series, on the outside of the house, there are two windows on each side of the front door. On the inside of the house, there is no window by the front door. The window is around the corner and to the left, and it is a little bigger than the one by the door as seen from the outside of the house. The house design on the inside doesn't match up to the design on the outside.
This episode is somewhat unusual in that it ends without the dilemma the characters are facing ever being solved. The viewers are left to assume everything is straightened out by the next show.
In this episode, Mr. Timberlake is played by Byron Foulger. In later episodes, Mr. Timberlake is played by Maurice Manson who plays Mr. Pomeroy in this episode.
An 1895 silver dollar is the rarest United States issue. It would have been worth many times the $600.00 value put on it - most likely $6,000.00 or more. In 2011, it is worth, in the lowest grade, over $100,000.
Dennis stands on Mr. Wilson's front porch and talks to Mr. Wilson who is looking out his upstairs window. This is impossible considering all of the upstairs windows are on the roof of the house. It is unlikely Dennis could hear much less see Mr. Wilson if he is standing on the porch and Mr. Wilson is upstairs by his window.
When Dennis is brought into the police station, Sgt. Mooney has no idea who he is. However, in episodes that aired before this one, he knows both Dennis and his parents.
In this episode, Mr. Wilson, initially, doesn't know how to whistle. However, in "Dennis and the Starlings," Mr. Wilson whistles just before he slams his front door.
In this episode, Dennis and Henry talk about Dennis taking care of a pet for an obligation. Henry mentions that Dennis used have a turtle but makes no mention of the bird Dennis got in "Dennis and the Good Example" or the frog that has appeared in many previous episodes.
Mollie Glessing is credited as "Molly Glessing."
In this episode, Mr. Wilson sneezes when he is around cats. In other episodes, however, when he is around cats, he doesn't sneeze.
The so-called 1919-D dime was in fact a 1913 Barber dime. The 1919-D would have been a "Mercury" head. Neither has much value except the silver content.
In this episode, Henry is allergic to dog hair and sneezes when he's around a dog. He is around dogs in other episodes but doesn't sneeze.
At the end of this episode, Dennis tells Miss Perkins that she is his favorite teacher. She tells him that she is the only teacher he has had. This is untrue as Dennis has had at least two other teachers by this point.
Henry tells Alice and Martha that the senator usually awards the presidency of the local chapter of the Horseless Carriage Club to the winner of the Horseless Carriage Road Race. However, according to the sign Henry has advertising the race, this year's race is the first annual. The senator could not have given the presidency to the winner of the road race in the past if this year's race is the first one.
The machine Henry uses to detect "GOLD,SILVER" looks and sounds like a Geiger counter. This would not detect coins or metals but radiation given off by atomic particles.
In this episode, it is stated that Dennis and Tommy have the same birthday. However, in an earlier episode, Dennis says that he and Tommy have traded birthdays.
In this episode, when the principal asks Margaret her name, she tells him that her name is Margaret Harrington. However, in most other episodes, she is referred to as Margaret Wade.