Only the Bad Come to Sonora - S4-E3
Plot hole: Manolito trades clothes with the poor peon he meets on the road. But at the end of the episode, he has the same clothes that he gave away earlier (his usual outfit) back on again.
Plot hole: This episode comprises a flashback to the year 1866, but it sets up a chronology that completely contradicts the rest or the series. It contends that the Cannons moved west to Arizona in 1867. In the pilot and throughout the series, it was stated that they arrived in Arizona in the 1870s, at least ten years after the U.S. Civil War.
Plot hole: The scriptwriter here apparently never saw earlier episodes in which it was well-established that Manolito spoke fluent Apache. In a scene where he attempts to sneak past two braves while disguised as an Apache, he suddenly can't speak the language when they challenge him.