When Kara is on her date, talking about her making Cat's dinner reservations, the position of her hand on the wine glass varies from shot to shot.
At around 39:23 when Kara is walking around Maxwell Lord in a glass holding cell, while they're talking, and the camera is focused on Max, you can see the camera man, and the camera in the reflection of the glass cell.
After the fake-Supergirl completes her transformation into Bizarro, the S-shield on her uniform reverses. While this is in keeping with Bizarro's comic book appearance, it isn't explained how her physical transformation would affect her clothes.
Hank days he'll have his team "reverse engineer" Kryptonite in order to give it opposite properties from normal. But "reverse engineering" doesn't mean to reverse something's properties. Rather it means to figure out how to build something or do something by examining a finished example of it.