Revealing mistake: When Diana is supposed to cut the power cables to stop the timer, just before she cuts the cable, you can see that all the cables are already cut and have a large, obvious seam in each of them. Then, when her hand goes through them, they all cut right at the seams.
Deliberate mistake: When Wonder Woman is bouncing around in the padded room, there's one part where you can tell the stunt double is not Wonder Woman.
Continuity mistake: When Wonder Woman tries to escape from the building, she's in the room with the padded floor and walls. Her heels are missing from her Wonder Woman boots, but they were on when she was in the hallway.
Continuity mistake: Diana is initially seen wearing a dark brown short-sleeved dress, but when she picks up the coffee, the dress inexplicably appears grey.
Continuity mistake: When Diana spins around, the computers are on. When she transforms herself into Wonder Woman, they're off.
Revealing mistake: Wonder Woman is in a control room with walls and a hard floor, but when she starts jumping around to avoid the lethal red light, the walls and floor swap to wrinkled and bending inwards, revealing it's a room covered with safety mats.
Continuity mistake: When the bad guy brings the suitcase to the control room, the time on the timer behind him jumps forward and backwards between shots; no continuity. (00:05:30)
Continuity mistake: Diana puts the seatbelt on the robot. A shot later, it's gone.
Continuity mistake: Before Wonder Woman jumps on the bad guy, he runs past a rectangular lid on the ground. When she catches him, he is metres behind, next to the rectangular lid again.
Answer: The first actress, Cloris Leachman appeared in the TV movie which ended up being the pilot for the series. At the time, Leachman was already starring in her own TV series "Phyllis" (a spin off her role in "The Mary Tyler Moore Show"). This was actually the 2nd TV movie meant to be a pilot and the first one wasn't picked up. It's likely she thought the show would be picked up. After season 1, in which Carolyn Jones played the role, ABC was slow to make a decision to pick up the series for season 2 and CBS picked up the series. When CBS picked up the series, they changed the time setting of the show and replaced all the actors, with the exception of Carter and Waggoner (with Waggoner playing a different role technically), resulting in Beatrice Straight being cast.
Bishop73