When Wonder Woman enters the burning barn it is daytime. When she drives the Jeep out of the burning barn a few minutes later it is pitch black night time.
When Wonder Woman saves Tommy from the ladder you can't see a door on top of the roof. But when she uses her lasso you see a door to the building immediately behind her. Why rappel down the side of the building when they could have just walked through the door and down the steps?
Steve runs from the curtain in a crouched position. The scene shifts to the gunman who fires the gun downward toward him, but in the next scene he is back over next to the curtain hiding behind Wonder Woman. In addition, the bullet is moving level at her shoulder level where she deflects it with her bracelet..
When Wonder Woman pulls back on the lasso on the Baroness, rather than being pulled back as physics dictates, she twists around and manages to lunge sideways into the pool. It is physically impossible for that to have happened.
When Steve is knocked unconscious, the shadow of a very heavy pipe wrench can be seen coming down with great speed and force. A blow with that heavy an object at that speed would either kill Steve, crush his skull, or sever his spine, depending on where he was hit.
The arm insignia on Diana's uniform is missing the Yeoman's insignia that should be located below the eagle and above the three red chevrons showing her rank.
The truck bursts into flames for no reason. It is simply rolling down the hill, hasn't struck anything and suddenly bursts into flames.
When Wonder Woman descends the rope with Tommy the light reflects off the wire that helps suspend the stunt woman.
The same shot of Tommy opening and passing through the gate to the secret tunnel is used both times he does so. As a result, he is not carrying his copy of "The Hound of the Baskervilles" the second time, as he is in the preceding and following shots.
Plainly ridiculous to see a grown man, in full army uniform, tied up in such a way, he could have stood up and walked away just like that. A gag over the mouth also serves no purpose. And Wonder Woman gets chained by what appears to be little more than ornaments. Tommy is held by rope it might take him not even a minute to free himself from.
At the end of the final fight scene Baroness Von Gunther tries to escape. Wonder Woman chases her down and they wrestle and roll down a hill. Christine Belford is wearing pantyhose. She should have been wearing thigh-hi stockings, as pantyhose were not invented until the late 1950s.
Steve Trevor's unit during the training exercise includes an African-American soldier. The United States military was not desegregated until 1948 (six years after this takes place).
Diana Prince could not have been a WAVES during the early part of the war. WAVES did not get to their first Stateside duty before 6 November 1942.
When Wonder Woman drives the Jeep out of the burning barn there is a black bar floating over her face and obscuring it. Clearly to cover the face of the stunt man/woman. Also, she isn't wearing her gold headband during that clip.
Whenever Wonder Woman uses her lasso it changes from golden when attached to her belt to ordinary brown rope.
During the final fight scene inside Arthur Deal's house, he fires a gun at Steve Trevor, and of course Wonder Woman deflects the bullet with her bracelet. You can see Lynda Carter holding the remote control devices for the pyrotechnics in the bracelets.
The location of the keyhole for the secret gate that the Warden uses is in a different location from where it was when Tommy used it.
Baroness von Gunther has the thin 1970's style plucked eyebrows instead of the normal fuller eyebrows women had in the 1940's.
Wonder Woman addresses Tommy by name, even though she has only met him as Diana Prince.
Tommy refers to Professor Moriarty, Sherlock Holmes' nemesis, as "Dr. Moriarty".