Yeah, I think it varies. At my school, there is a prof who, this year, interviewed five stellar people but got a bad "vibe" from all of them. Late February, he calls up another five and brings them in for an unofficial interview and accepts someone from that group.
However, I do think this is an exceptionally rare occurrence. I'm trying not to let myself hope for a situation like that, because I feel it would be a false hope and I don't think I could intentionally set myself up for that kind of disappointment.