The Met Police haven't said Gavin Williamson has done nothing wrong. They said a crime was not committed.
There's a big difference in those two statements.
Assistant Commissioner Neil Basu, the head of the Met’s Specialist Operations, said:
“I have spoken to the Cabinet Office regarding the nature of the material that was discussed in the National Security Council. This material was used to inform a discussion, the outcome of which was subsequently disclosed to the media. I am satisfied that what was disclosed did not contain information that would breach the Official Secrets Act.
“I have considered all the information available to me and I have taken legal advice. I am satisfied that the disclosure did not amount to a criminal offence, either under the Official Secrets Act or Misconduct in Public Office. No crime has been committed and this is not a matter for the police."