Revealing mistake: When Henry's mom is pushed off the cliff her cable is visible.
Revealing mistake: When Henry throws the dummy off the bridge, watch the rear window of the gray car; it explodes before being hit.
Revealing mistake: In the shot immediately following the multiple car collision, there are no people either in the cars or on the road.
Revealing mistake: After Henry falls dead on the rocks, a black cable is visible that is attached to the supposed corpse of henry and to another rock ground level, possibly to stop the dummy corpse from drifting away.
Answer: Henry apparently has what is called a "conduct disorder" - the term used for kids below the age of 18 engaging in what would be (and most likely will become) a diagnosis of sociopathy/psychopathy (antisocial personality disorder) when he becomes an adult. He is "evil", highly manipulative, self-centered, without remorse or other true feelings, and probably incapable of forming loving or long-term attachments. Many sociopaths are believed to have above average intelligence and make good imposters, capable of fooling others because they come across as "charming."
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