I'd bet on the opening harmony being autotuned, because it's just a little too perfect and shiny. But after that it gets less clear. There's quite a bit of timing slop on the vocals, which suggests live recording for at least some of the harmony lines.
Not that I'd want to be too picky - it's a very good cover, and I like it a lot more than the original.
And of course, there's no promise to show every sample they recorded, just the ones they used. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
