Maybe he sounded good but it's heavily pitch corrected (no need to ask Fil from wings of pegasus I think we all know how weird it sounded but yes even Fil proved it already) I think his voice would have sound good but sadly we will never get to hear it, very sad actually, now we can't even get to hear raw vocals from voice competitions, isn't that crazy I mean wtf. Recently this young artist Benson boone sang some queen totally live with Brian May, I appreciate the fact that is really live.  Check it out Brother! He's very consistent throughout all of his shows.

Might be autotune because his voice has artifacts on high notes, as you’ve noticed as far as I remember from your video. Might be tune on root notes from midi record. I guess the settings are pretty rough because computer can’t tune everything unnoticed, he should’ve hit those notes at least close. Might be his weird timbre but overall there’s no timbral unity through the whole thing. So in lower notes his voice sounds way more natural than on higher ones so 95% tuned. Real time tune I guess. This is Something Got Talent, there are no real talents.

Technique is basically m1 overdose kind of how I sang lower notes of “the kill” chorus. IMO. Or how I tried to shout A#4 in man in the box. 

To my mind his chest ends on F#4-G#4 like most of ours. So these highs are too difficult to sing like that consistently with his bigger kind of voice. Tenors don’t sing like that.