It's a good thing Doug Drinen doesn't browse these forums that often, otherwise he'd be annoyed with me for posting a seven-year-old link. That said...
http://footballguys....nen_garbage.htm
"A case could be made that Arizona's generous endowment of garbage time added 48 fantasy points to Boldin's 2003 total."
If Boldin had 139 fantasy points instead of 197, it still would have been a very good rookie year. But not the sort of ZOMG year that has people talking about it seven years later. It appears that garbage time helped him quite a bit.
Of course, lots of rookie WRs play in garbage time. The Panthers and Cardinals had some rookie receivers play in a ton of garbage time, and they didn't do much. Jeff Blake, while actually a decent quarterback for the majority of his career, was washed up by 2003, his last year starting. He was a shell of the player he was in the late '90s by then. But Marcel Shipp and Emmitt Smith weren't very good, and Arizona was very, very thing elsewhere at receiver. I think that was probably the biggest factor in making him different than any garbage time receivers. The pie wasn't all that exciting in the desert, but Boldin ate the whole damn thing.