The Night That Terror Stalked the Town - S1-E10
Revealing mistake: During the final scene where West and his double, Janus, are shooting at one another, the two look identical to one another. West goes to the roof and jumps off onto Janus who is by the cannon. However, the revealing mistake is the original looking Janus is playing the role of West diving off the roof, and the one who is fighting Robert Conrad who is supposed to be playing his double, Janus, is standing by the cannon. When the two begin to fight on the ground, one should not be able to tell the two apart, but it is apparent the faces are different. The mistake is fixed when the two get off the ground and now both fighters look like West.