When Diego stomps the two horseshoes into the dirt to demonstrate the difference in the tracks they'd make, the horseshoes are nearly one on top of another, long ways, and he leaves a noticeable boot print around each horseshoe. After he has removed the horseshoes and the prints are shown in closeup, the prints are nearly side-by-side, and there are no distinct boot prints.
When Zorro sheaths his sword after defeating the bandits, he misses the sheath completely, yet in the next shot, the sword is suddenly properly sheathed.
When Zorro comes across the three bandits arguing, the sound of their voices doesn't match the movement of their mouths.