Revealing mistake: After the explosion we see a shot of the fire in the second story window, and when Wonder Woman leaps up to the window the smoke is going into the window instead of out, which reveals it's shown in reverse. The boots she's wearing are also flats which then change back to heels.
The Man Who Could Not Die - S3-E22
Revealing mistake: When Bryce shows up at Dr. Akers' place and asks for the briefcase, he is replaced with an obvious stunt double, chubbier and with a funny big wig.
The Man Who Could Not Die - S3-E22
Revealing mistake: Obvious fireproof gear and a mask when Bryce escapes from the fire.
The Man Who Could Not Die - S3-E22
Revealing mistake: When Wonder Woman jumps towards the window engulfed in flames, the fire moves backwards inside the building, revealing how the jump and the scene were really shot.
Revealing mistake: When George hangs upside down on the building ledge, the safety cable holding him is visible.
The Girl with a Gift for Disaster - S3-E19
Revealing mistake: When the gas truck crashes against the blue car, it already has a dent on the door. After the crash, the dent disappears and the door gets fixed.
Revealing mistake: When old Mary Jane Thrip kicks the bad guys' ass and runs away, her younger stunt's face is visible.
Revealing mistake: Visible ramp to allow Wonder Woman to jump over the van.
The Richest Man in the World - S3-E17
Revealing mistake: When Wonder Woman pushes the gunman off the beam, he falls on a very evident crash mat covered with a black canvas.
The Richest Man in the World - S3-E17
Revealing mistake: During the chase, when the car overtakes a red car, Henshaw's stunt is noticeable because of his bulky wig.
The Richest Man in the World - S3-E17
Revealing mistake: During the car chase scene, skid marks from previous shots are everywhere. (00:32:13)
The Richest Man in the World - S3-E17
Revealing mistake: When Henshaw and Barney's chase starts, there's a shot inside the car where it's painfully obvious that the car is not moving at all. Check how the reflections on the hood are perfectly still, for example. (00:32:08)
The Richest Man in the World - S3-E17
Revealing mistake: When Wonder Woman is chasing the guy at the factory, their stunt doubles are noticeable.
The Richest Man in the World - S3-E17
Revealing mistake: Skid marks from previous takes are on the dirt next to the cliff where the van heads to.
The Richest Man in the World - S3-E17
Revealing mistake: The upper edge of the set is visible during the event. (00:02:55)
The Starships Are Coming - S3-E15
Revealing mistake: When Wonder Woman is fighting against all of the thugs, one with a brown shirt and a pair of jeans is knocked out, but her punch misses by far.
Spaced Out - S3-E14
Revealing mistake: At the Black Avenger's room, when Kimball removes the grappling hook, the sky in the background is a very obvious backdrop where the wall has a seam line running along.
Spaced Out - S3-E14
Revealing mistake: At Paragon Studios, the actors' marks are visible on the floor.
Spaced Out - S3-E14
Revealing mistake: When Kimball climbs the hotel wall and all subsequent shots of him running, his stunt is evident: straight hair as opposed to Kimball's curly hair.
Revealing mistake: When Wonder Woman is swimming in the sea, it is obvious that she is in a swimming pool instead.
Answer: Not just Grundy but everything that could link Diana and her Wonder Woman identity. A links to B, then to C.
Did Randy know that Diana was really Wonder Woman?