It was August 2011.
According to information provided to the Minister of Public Safety, only two people have ever signed out that specific file, and this information has been provided to the minister by the court in Manitoba. One person connected to the NDP signed it out in February of this year after Vikileaks30 broke, but the other signed it out in April 2011, during the federal election. I can only assume that it was provided to the Liberal Party then.
You have no idea how the Liberal Party came to have this court document, which you indicate was publicly available, which it was. But you had to go to the province of Manitoba, specifically, to obtain it. You've never been to the province of Manitoba, or you haven't been there specifically to retrieve this file.