Revealing mistake: When Mary enters her husband's secret room she lights up the room using a paraffin-oil lamp, but the room lights up before her match has reached the lamp.
The Actress - S4-E22
Continuity mistake: Little Joe falls in love with Julia Grant, an aspiring actress who, with her son, is staying at the Ponderosa for several days. After she learns she has landed an acting job in San Francisco, she and her son leave the Ponderosa. As they ride off in their horse-drawn wagon, Joe is standing next to Ben and Hoss and he is waving goodbye with his right hand. In the following long shot, Joe has both hands on his hips and is staring at the ground.
Other mistake: At night, Adam goes to visit a man whose brother has been shot and killed. After the man lights a lantern on the table to Adam's right, Adam's shadow is to his right and not to his left as it should be.
Continuity mistake: In the Ponderosa home, Arturo Diaz, a Mexican freedom fighter, is shot by a renegade pistolero. Diaz falls on his back and Ben Cartwright rushes to his side. Diaz says "Adios" and then dies, with his head turned to the left. After a brief close-up of Ben, Diaz's head is now turned to the right.
Factual error: Walter Prescott accuses Hoss of "two-timing" him with a mail-order bride. This episode is set in the mid-1860s and, according to the Merriam-Webster dictionary, the expression "two-timing" dates from 1924.
Visible crew/equipment: Joe and 4 fellow stagecoach passengers are in a cave. A fist-fight between Joe and another man ensues just outside the cave. At one point, a rubber tire is visible in the lower left of the screen. (00:40:15)
Saga of Whizzer McGee - S4-E30
Continuity mistake: When Whizzer is pouring coins from a robbery into the hands of Melissa, she is wearing gloves in camera shots taken from one angle, but have bare hands in shots taken from another angle. This mistake is repeated 8 times.
Audio problem: During the trial of gunslinger Duke Miller for murder you can hear repeated sounds of the gavel being hammered down by the judge. On several of these occasions you hear the gavel but the judge never moves, nor does he have the gavel in his hand.
The War Comes to Washoe - S4-E7
Other mistake: In early evening, Hoss and Adam discover the body of a man who had been shot with an arrow and killed. Even though it is still very bright sunlight, Adam lights a match and holds it close to the man's face so he can see who it is, then lights another match so he can read a letter that was in the man's coat pocket.
