I'm hearing a lot of suddenly conflicting info. Besides the above by Kingcreek, also that he was legal but used a fake ID for E-verify (why would you need fake ID in that instance unless you were some other kind of criminal?). So besides fishy stuff going on, looks like we'll need to wait for some dust to settle to get the actual facts.
The fishy stuff was from his lawyer who has stopped claiming he was here legally.
The farm claims that they used the Social Security verification service, not E-Verify, but that the person who used it thought they were the same. (Why is the government providing multiple means of verification, btw? Especially since it seems one is easily fooled. Of course, that may be the point, too.)
So, after it's cleared up: he was here illegally, the farm has plausible deniability (even if I don't believe them), the lawyer is a sleazebag, and the media are a bunch of hacks who jump on every tidbit without any verification that might help their cause. Everything comes up exactly as expected.