Near the end of the film it rains heavily, but a short time later the ground is completely dry.
After her second escape attempt, immediately after emerging from the pond, as Julianne moves towards the truck, and then in the close-up on her in the cabin, her clothes are completely dry.
The film takes place in an isolated location, but when Mitch is teaching Julianne how to fish, a car drives through the background.
After shooting the stag, a chop is thrown into the pan, the bone of which is neatly sawed, the meat clearly professionally slaughtered with a meat saw, a large, heavy electrically-operated piece of equipment, on this small island with no modern conveniences.
At 1:01:59 a directors chair is visible in the background.
After Mitch sinks the rowboat, the only dry way to get to the far shore, he goes to town for matches, getting to the truck dry, and then returns dry with a lit cigarette after presumably swimming to the island.