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)
Continuity mistake: Maddox has blue eyes as a teenager and dark brown eyes as an adult.
Other mistake: How did Trent (who started as a six-year-old) end up with an adult-size watch and bracelet?
Answer: I submitted this answer previously, but it was deleted for maybe appearing to be inappropriate. The reason for his slower aging is addressed in the film when he says "Black don't crack." Black people tend to age better than other people in real life, due to having a higher production of melanin and other factors.
Phaneron ★