Factual error: At an 1868 church service, Mark sings "How Great Thou Art." While the tune of this hymn is 19th Century, the English lyrics he's singing weren't composed until the 1920s.
Other mistake: As the 2 buffaloes are walking out of the scene at the top of the hill Charlie says to Clyde that 'it's either gonna be her or me' but as both buffaloes' bellies are exposed in the same shot, it's clear that both buffaloes are males, or bulls.
The Frank Carter Story - S5-E34
Continuity mistake: At the end of the episode, Duke is riding back to wagon train and has a gun holster on his left side. However, when he rides into camp the gun holster has switched to the right side. (00:48:00 - 00:49:00)