It was a very serious breach. Unfortunately, Mr. Harper's response at the time was that it was a personal matter and that there was no need to get involved. He allowed the person at issue to keep his job.
Evidence of meeting #72 for Procedure and House Affairs in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was campaign.
A video is available from Parliament.