I doubt there will be charges brought either, as it will be difficult to prove.
Brown Darling and Robert Peston is different though, isn't it - Robert Peston is not a government employee and presumably did not solicit the information, it's just assumed he would want it, as a BBC journo.
They shouldn't have leaked the information, but that's the not the same issue as someone deliberately encouraging a civil servant to break the law.
Passing confidential information to anyone not allowed to view it is illegal - the civil servant was clearly breaking the law.
Aiding and abetting and encouraging someone to break the law is also illegal.
But leaking information you have received that you didn't ask to receive is tolerated if it's in the public interest. So if Damian Green was passed the information without asking for it, he could leak it. But if he was asking this civil servant to pass it to him, especially if he was promising advancement of some sort in return, that's very serious, especially considering where this man worked and the level of access he had.
The lack of a warrant seems to have been a fuck up, but I REALLY don't believe that Special Branch would fail to tell the Serjeant at Arms that they had the right to refuse the search, that's basic police procedure. I suspect some arse covering going on.