Continuity mistake: When Batman and Robin are in the museum speaking with the director, Batman's chest emblem is high enough on his chest that it nearly touches the bottom edge of his cowl. In the next shot, when he leaves the museum, the emblem has moved down several inches.
Audio problem: Joker's TV debut as an opera singer isn't very convincing. Even through the partially-obscuring clown mask, you can see that his lips aren't moving at all. (00:22:30)
Continuity mistake: In close-up, Bruce Wayne folds his newspaper in half, leaving the folded edge facing the camera. The shot cuts to a wider view and immediately, the paper has reversed positions in his hand. (00:04:00)
Revealing mistake: In this episode and the next one, Robin's stunt double is very obvious from the back, especially in the scene where they enter the Hall of Fame museum.
Visible crew/equipment: When the museum closes early and Joker calls to each of his cohorts, their individual chalk T-marks are visible on the floor where they all stand. (00:12:40)
Visible crew/equipment: When both Batman and Robin realise that even though the museum can't be broken into, it doesn't mean someone couldn't break "out" of the museum, as they rush to the museum's front doors we can see a chalk T-mark on the ground in front of the doors. (00:13:25)
Visible crew/equipment: At the end, Joker announces the unmasking of Batman and Robin, then when Joker turns and walks toward them, multiple chalk T-marks are visible on the floor where the dynamic duo are being held. (00:23:55)
Revealing mistake: At the start, when Joker has sprung himself from prison, there are three shots of the giant spring, and the wires holding up the platform at the top are visible. In the third shot, one of the wires even glistens for a moment as it moves. (00:02:35)
Continuity mistake: Batman and Robin are being summoned by Commissioner Gordon, but are still in civilian clothes, so it's time to get to the Bat-cave. Bruce presses the switch and the bookshelf begins to slide open. Pay attention to the white books in the third row and the red books on the top shelf. In the close-up that follows there are fewer white books, their cluster aligned with the last of the red books, a different proportion from the previous shot. The name tags on the bat-poles are also misaligned in the wider shot and perfectly at the same level in the close-up (which is a reused shot from the pilot episode). (00:05:10)
Continuity mistake: Despite his lackadaisical pitching, the Joker manages to eliminate a series of batters. In particular, there is one elimination before and after the warden tells O'Hara about the joys in life, when Joker didn't really have time to throw the ball 2 more times. (00:01:55)
Other mistake: The Joker's escape is so cartoonish and ridiculous you wouldn't even know where to start; besides the fact that the explosion somehow engulfs instantly the whole baseball field, the guard on top of the wall is following his movement with the gun, so he sees the Joker, therefore the smoke screen is useless, not more effective in any way than the mere surprise of a coil suddenly springing up from the ground.
Continuity mistake: The Joker sends a doll crashing through the window of Commissioner Gordon's office. O'Hara is holding in close-up the doll in a different way from the wider shots, and the jester cap of the figurine is also blatantly folded in a different fashion. (00:18:30)
Revealing mistake: To free himself from the Joker's goons, Batman throws a gas capsule on the floor. Two things; first, the Joker is instantly asphyxiated by a lot of smoke, but when the henchmen let Batman go in the next shot, the puff of colored fumes has barely started to rise, and the Joker is further away. Second, the capsule that Adam West throws with panache on the ground and that should generate the noxious cloud can be seen actually bouncing back up after his energetic toss. (00:15:30)
Continuity mistake: Arriving at the museum, the dynamic duo is greeted by some rabid Robin fans; when they start screaming and cheering for him in a close-up, there are men passing by behind them that were not there in the wider shot with the Batmobile approaching. (00:09:40)
Continuity mistake: When Joker shows off for the first time his utility belt, it switches sides between shots. First each pocket has its buckle on the right, towards the blonde bimbo, then in close-up the buckles are on the left, and when it switches back to a wider angle, again they are on the right. (00:16:45)
Continuity mistake: The first fight, in the museum, besides the obvious dose of wild haymakers has a rather messy phase when the "THWAPP!"; appears; Robin is facing two enemies, but the one with the red shirt lost his hat, which is back on in the next shot (and was on in the previous). (00:14:10)
Continuity mistake: Everytime the Joker is shown on TV his hair is brown, but before and after the broadcasts, it's his usual green with no time for him to change it.
Answer: It's wasn't unusual for multiple actors to play one character on this show. The villains on the TV Batman were played by guest stars, not regular cast members. George Sanders, Otto Preminger, and Eli Wallach played the part at various times. They may simply have only wanted to play the part once or twice, or they were later tied up with other projects, making it necessary to cast someone else. Other characters, like Catwoman, were also played by more than one actress.
raywest ★