My guess is that he will deny seeing the file and was only repeating what "someone, somewhere" had said. It would be better to claim to be a gossip than to admit to having seen the file, which would have broken the law.
If, in fact, he did break the law, Allen (VA) said on Tony Snow that he would follow through with the Ethics Committee (of which I believe Reid is a member - irony).
Somebody had to break the law because if Reid himself didn't see the file (which would be illegal) then someone had to tell him about it's content (which would be illegal).
Unless he is just plain lying which would be unethical.
In any case I think we need a committee to investigate, a mans name has been irreparably damaged.