I'm with you on that. It's not easy felling a tree. The notch looks a decent cut, it's easy to go too deep, and the felling cut is smooth and clean. Done quickly in one go too, you can see by how little of the trunk has broken at the end as it fell. Staying that close to cut that far takes some balls, which suggests an experienced individual ( or they're just 'kin stupid)
Not a small tree either, you'd need a decent sized bar, not a 12" one you'd pick up at B&Q.
I'm doubtful that a 16 yo has got the tools or the experience to do a job of that quality.