Other mistake: After they blow up the dam blocking their passage, there is a far away shot as they are going up river and there's a grassy landmass that goes across the river blocking their route up river.
Continuity mistake: Jennifer Lopez's eyebrows go from sparse to filled in in several scenes.
Continuity mistake: Serone catches a fish using a spear and then chops it up with a knife and a mallet. He then talks to the crew about their documentary and walks back to the chopping board where he proceeds to chop the same fish again, which is now whole. (00:12:32 - 00:13:21)
Other mistake: When the anaconda is behind the boat she shoots at it about 5 times with a bolt-action rifle, with no magazine, and never reloads.
Answer: A snake can regurgitate its food, but they do this mostly if they are in danger or stressed, not to go after another prey or swallow it again so it's easier to digest. The food is usually quite a weight on their body and takes long to digest, so the snake could regurgitate it to become mobile again if threatened.
lionhead