At around 30:00, Amy is walking on the motel's outside corridor, which is visibly empty. In a jump cut a moment later, as she turns around to the lady who is yelling at her, she bumps into Frank who is just about to leave his room.
While this happened in a split second, it is entirely possible and plausible that Amy could not see that the door to Franks's room was open and that he was just about to step through it.
While this happened in a split second, it is entirely possible and plausible that Amy could not see that the door to Franks's room was open and that he was just about to step through it.
It would be virtual impossible to find a motel (especially along a highway) that doesn't have a keycard access on its rooms. It would be so unusual that Amy (Rachel) should have been surprised.
When Dinah takes a drink from the flask, the flask is not open. The cap is still on the flask as she holds it to her mouth.