Catwoman (2004)

Revealing mistake: In the jewellery store when the robbers are smashing the display cases they shatter before being hit with the shotgun butts.

Revealing mistake: In far shots of Catwoman walking towards ledges, such as the scene where she lands on the overlooking porch in the mansion, and moves to fall forward to the floor ahead and when she walks the top buildings, you can tell it's a CGI character by the way she falls from one level to another because the character's body doesn't react/shift the way it would if it fell from one level to another. You can see the character standing straight and as it falls a short distance it's still standing straight without any sign that it even fell.

Revealing mistake: When one of the robbers is about to hit the glass in the jewelry store the glass breaks when he hits it, but if you see closely when he's about to hit it you can see that the glass actually breaks first.

Revealing mistake: When Patience escapes from the jail cell by slithering herself through the metal bars, it's obvious that one of the bars is made of rubber or another soft material. One can easily see it bend to accommodate her body and then go back to its original shape.