Revealing mistake: 1967: Barnabas and Vicky are talking in Collinwood's foyer when a great deal of noise starts interrupting the scene from backstage. You can hear coughing, several bumps and crashes, shouts, and finally, a fire extinguisher going off. Meanwhile, the distracted actors are completely blowing all their lines - but the unstoppable taping goes on.
Revealing mistake: Batman drives out of the batcave alone. The first bit of stock footage of the car leaving the cave does indeed show him alone in the batmobile. But the very next stock shot of the car speeding down the dirt road shows us Robin sitting in the passenger seat. (00:05:25)