I wish the article had more on what reasons the RCMP gave for not going through the established treaties to get the data they're after. The fact that the judge went along with it implies there was some reasonable justification, though the only one that comes to mind is that their request would have been rejected according to the terms of the treaty. Though, even then, why isn't there some route where the mounties cooperate with the gendarmerie, keep French data in France, and still create a legal case in Canada.
This whole attempt seems to be as much against the long term interests of Canadian sovereignty as it is for French sovereignty.