Graded clinical years are lame.
They're totally subjective. First of all, many schools can have artificial grade inflation; I've heard of places where they hand out 50% honors. My own institution used to have a problem with the FP rotation because it was so incredibly easy to get honors that it was a joke - that has since been stopped (but now it's the reverse, which is also pretty lame). Second of all, clinical grading is why ass-kissers do so well. You get an honors for laughing at bad jokes, grinning like an ape, throwing around compliments, being a gopher ...oh, and sometimes actually knowing something. And if you're friends with the residents/attendings, that's an automatic honors. Whereas, if you're quiet and not as extroverted or just not an ass-kisser (especially if you are on the team with someone who is) you may eke out a pass.
I once was on a team for 2 weeks with one resident and then the teams rotated. I was paired up with a female and the first resident was a male. He fawned all over her, helped her with everything, prepared her for pimping sessions, and reviewed her progress notes. Meanwhile, I received no help, got stuck with mostly combative patients, and was generally on my own. Then the teams switched and the new resident was a female. We finished out the rotation and she gave me her evaluation. (Paraphrase, but this is the actual gist of it with no sarcasm): "I was surprised. The other resident told me that you were lazy and pretty stupid, but I didn't find that to be the case. However, since he gave you such a poor review for the first half of the rotation, I'm going to be forced to give you a pass."
That's why you worked so hard to get into medical school: so that you can get dicked over in some popularity contest. Or so you can watch some oversexed guy/gal try to hit on a medical student in exchange for grades. It makes you feel all warm and fuzzy inside.