The Night of the Kraken - S4-E6
Other mistake: While walking on the waterfront after the bar fight, West and Aguila's clothes are dry where moments before they dove out a window into the ocean.
The Night of Miguelito's Revenge - S4-E12
Other mistake: The sandbag that almost falls on Pike and West splits wide open upon impact with the floor, but subsequent shots of the bag show it almost intact.
The Night of the Spanish Curse - S4-E14
Other mistake: Very close to the end of this episode during the fight scene, West and Gordon throw a guy directly into the camera - causing the shot to become unfocused and shaky.
The Night of the Plague - S4-E24
Other mistake: In the last fight scene, West runs uphill from the cave entering the scene from the most east side of the screen. There is a bad guy on the ground to West's right side as West is running uphill. The villains chase West, but their shot shows them entering the same scene from the middle of the screen with the guy on the ground on their left side.