Revealing mistake: The "Anamika Resort" van isn't quite in sync with the road it is supposed to be traveling on. A side view shows the van is traveling straight ahead, but a shift to a front view shows the road behind the van is curved to the right. The same thing happens a little later, except the road is curved to the left. (00:01:19)
Old (2021)
1 revealing mistake - chronological order
Other mistake: How did Trent (who started as a six-year-old) end up with an adult-size watch and bracelet?
Trivia: The driver of the hotel van service taking the guests to their secluded beach is none other than the director M. Night Shyamalan. He has a speaking role in this movie as well.
Question: Why didn't the lady who was originally with Mid-Size Sedan decay quicker, and we were able to see her body intact when she hit young Trent in the water?
Answer: Because she was 'freshly' dead when she hit Trent.