http://pulsemusic.proboards.com/index.cgi?board=gmn&action=display&thread=82723

That's a link to an American music forum, Pulse. The lists were leaked somewhere in the 30s, and I see one member saved the lists and copy/pasted "best female pop performance" on page 40. Utada is #145 (it's ordered alphabetically by name, doesn't mean she had the 145th best song or anything)

I think that this would be enough evidence because (1) so many people wouldn't all conspire to pretend those links were there through about 10 pages of forum, and (2) whoever copy/pasted the lists wouldn't have wasted their time making that up.