Corrected entry: The Cartwright family's Ponderosa Ranch is located on a huge tract of land near Virginia City, Nevada, but in this episode only, the ranch is said to be in western Utah.
A Stranger Passed This Way - S4-E23
Corrected entry: About 5/6 of the way through the show, out in the barn with Joe and Adam, Hoss, who is supposed to have amnesia from a blow to the head, thinks that a couple, the Vandervorts, are his parents. Mr. Vandervort calls Hoss from the house and Hoss responds by calling him Mr. Vandervort instead of calling him Pa or Dad. He still thought he was his father at this point in show.
Correction: You apparently did not watch this episode very closely, as there was no mentioning of the Vandeworts as the "parents" of the blow stricken Hoss Cartwright.
Corrected entry: After reading a book titled "The Art Of Bullfighting," Hoss and Joe get into an argument about the definitions of certain bullfighting terms. Joe says, "I think you've been reading that wrong book." Hoss retorts, "I think you've been reading it upside down." Joe meant to say, "I think you've been reading that book wrong."
Correction: Joe actually says "I think you've been reading out of the wrong book". He didn't flub the line and what he said makes perfect sense. Hoss' reply was just him trying to comeback with his own quip without repeating Joe's insult.
Corrected entry: In the opening scene, the blackboard has area = PI squared R. Area of a circle is PI R squared.
Correction: While the superscript 2 is close to the PI symbol, it's merely because of the writing size. The r is closer and meant to be r squared (if we had seen her write or say PI squared, that would be a mistake).
Corrected entry: The head of the Virginia City Merchants' Association is officiating at a "Beautiful Baby" contest. At three different times, he tells the four-piece band behind him to "play some music." Each time, without any discussion of which song to play and without anyone counting "one-two-three," the four musicians immediately begin playing a tune, a different one each time.
Correction: Bands practice quite a bit and know what songs they'll play and in what order, here they simply waited for their cue to play. My mom plays in a trio and during their performances, no one has to say "1-2-3", they just start playing (one person is assigned to start the piece and the others follow because they know when the first note will be played).
Corrected entry: About 3/4 of the way through the show, Ben takes the dog tags from two soldiers as proof they are ready to give up. The problem with this is the US Army didn't start using them until late 1906, and Bonanza is set in the 1860s.
Correction: In 1906, the circular aluminum disc was introduced for use by the U.S. Army (and then made mandatory in 1913.) However, at the time of the Civil War, soldiers in the Army would carry various forms of identification. However, Cartwright never calls them "dog tags", he says "name tags." And you can see they are made of paper, not engraved metal, to fit the time period.
Correction: Utah Territory was the name for the present-day states of Nevada and Utah.