The Return of Wonder Woman - S2-E1
Factual error: When Steve gets attacked by the bad guys and Wonder Woman shows up, the lady in the car pulls out a camera and films the event. She sits still, the car isn't moving, and she does all the filming from the same position. However when she watches the playback, the film shows footage from multiple angles and varying distances, which is impossible because she and the camera were in the same spot the whole time.
Wonder Woman Meets Baroness Von Gunther - S1-E2
Factual error: When Wonder Woman is running toward the burning Old Virginia Stables, she passes a modern 1970s era vehicle parked on the road.
Wonder Woman in Hollywood - S1-E14
Factual error: Wonder Woman is flying to Hollywood, and the iconic sign is shown. However, in the early 1940's (when this season is set), the sign read 'Hollywoodland'.
Factual error: In the opening sequence, a man placing dynamite on the truck is dressed in a camo-type uniform. This type of clothing was not introduced until 1981, and the episode was set in World War II.
Suggested correction: The camo type/color seen was around during WWII. It should also be pointed out the mistake claims it wasn't introduced until 1981, but the real life filming occurred in 1976. So they can't have been using camo type during filming that wouldn't even be introduced for another 5 years.
The New Original Wonder Woman - S1-E1
Factual error: When Wonder Woman drops Steve off at the hospital, the nurse (a first lieutenant) is wearing her silver bar vertically on her collar. It should be horizontal.