I know it's probably my imagination, but it feels like there is very subtle pitch correction going on all over the place. For instance, check out the weird phasing of his voice around 4:22-4:24 as he's going "oh-ah-oooooh".
A buddy of mine used to work as a recording engineer and the most soul destroying parts of his job involved auto-tuning rich kids who had way more money than talent.
Listening to this abomination on good equipment is torture. Pretty much every part is heavily autotuned and eq'ed in a shameless manner. Oh well, fuck the parents!
Whoever was doing the autotune work did a good job of hiding the most blatant problems with it (meaning they spent a LOT of time and therefore money on it), but yeah there is clearly a lot of tuning going on.