Continuity mistake: Mano throws a lasso around part of the burning hay wagon and hauls it away from the building. The camera angle changes as the wagon is pulled out, and from one shot to the next, the flames completely disappear.
Revealing mistake: At the end, we see insert close-ups of several of the pueblo's residents. But they're exactly the same shots we saw near the beginning of the episode: the same people in the exact same positions, shown in the same sequence. The footage is recycled.
Revealing mistake: During the fiesta, Reno plays his guitar in the canteen. Each time the musical chords change, we should see his left hand shift positions on the neck of the guitar. But though his right hand is vigorously strumming the strings through several chord changes, his left hand never moves.