Lex is deeply involved and has been since he was nine years old, and has every right to investigate the meteor rocks - or, for that matter, the time he could have died.

Not to mention Lex having every right to investigate the unearthly metal octagon he found in the same field where a spaceship may have crashed, and the apparently dangerous and extraterrestrial parasites found in the caves he's been safeguarding, and the seemingly alien writing in those caves, and...actually, aside from the photos of Clark and the Kents, I can't think of anything in that room that Lex didn't have a perfect right to be studying. I just wish someone had pointed that out to Clark! *growls at dense, self-righteous Kryptonian*