When Amy, Mark and Kyra first reach Little Betsy, Mark is standing somewhat behind Amy. In the next shot when Amy waves and says, "Nice to meet you, Little Betsy," she is alone in the shot. In the next shot, Mark is standing in the previous position somewhat behind Amy again.
When Amy and Kyra go down from the balcony to speak to Hunter, Peter is standing next to the stairwell. In the next shot, Peter is standing on the other side of the balcony with Mark and Tara.
Mark takes Amy to a special spot to see the "crescent moon". One or two days later a full moon is seen.
When describing how he got to the illusive waterfall he used Angel Falls as a reference and a certain rock. When they go to Angel Falls it takes two days. At the end of the movie Amy finds the rock in less than a day.
When Amy is at Redwood Falls and says, "I took the scenic route," her mouth movement does not match the word "route."