Continuity mistake: She doesn't have an undergarment when she wears the blue shirt, and suddenly in the cave, when she removes her shirt, she is wearing a black undergarment. (00:16:52 - 00:55:55)
Suggested correction: She may have changed her underwear after Stan raped her. She was also wearing pink panties during the rape scene, but in the scene after, she is wearing black panties, so it's plausible she changed into a black undergarment at that point.





