The Doctor lays out six plastic squares to form a circle, but in the next shot they form a cross.
Mexican bandit leader Arturo Villar is wrongly credited with the forename Arture.
When Villar attacks the Doctor in the processing room, the guards are seized by the other resistance leaders and dragged off-screen. Shortly thereafter, the extra playing one of the presumably incapacitated guards can be seen in the background behind Jamie, looking on and grinning.