I might believe it if he had an 85 IQ.
But if he was intellectually avg, & 12 yrs old when his father supposedly took him to live in the woods, he’d certainly know his full name and where they used to live.
Sounds more like a runaway
Yes, that’s possible ... but if he’s 17 and intellectually average, he’s perfectly capable of making the whole thing up, with some evidence that will seem reasonable to start with.