When Clint is at Jessie's Grocery, he picks up the rope that was attached to the boat and says that it was "clearly chewed through". However, if you look at the close-up shot of the rope, it was very clearly cut, not chewed.
When Iris is running through the forest away from the frogs, they make a big deal about her knees: she falls and they get all scraped up and bloody. However, in the next subsequent shot, her knees are suddenly all better.
After the man goes into the greenhouse and he gets killed by the lizards knocking over the bottles of poison, we see that it's very smoky in the greenhouse. The smoke is so thick that we can barely see through it. However, less than a minute later, Smith opens the door to the greenhouse and it's perfectly clear.
When Smith is driving through the forest, it's supposed to be nighttime. It's dark both in the forest and in the shots we see of the plantation house. However, when they show other shots, it's obviously daytime because you can see the sun and the clear blue sky.
When Pickett Smith (Sam Elliott) escapes with his family by a canoe, he is wet, because he was in the water (shirtless) untying vines of the boat; when all family reaches the land, he is completely dry.