Wow, what a strange story. While I can’t help but think something is so suspicious here... I just can’t help but think that 11 people is too many to all agree to cover it up. Unless they all had the same motive to hurt him and hide him but that’s extremely unlikely. Even if just one person snuck off with him and hurt him he would have been found relatively quickly I think.
So sad for this bright young man’s family, it’s been far too long without any answers.