This type of discussion is a difficult one to have. There have been enough legit unanswered questions asked here (not the least of which being whether those alleged to be involved were even Police) that I wouldn't automatically take this posting as a reflection on the hard work that the fine folks at BPS do for us every day in order to keep us and this community safe.
There's a segment of the population that looks for any reason to hate on Police and that can include taking details of stories such as what the OP has posted as gospel. Police in general aren't above making mistakes but I'm going to guess that accounts of misconduct far outnumber actual incidents of it and that that disparity doesn't make the job any easier. I'm glad to see so many folks asking questions. Personally my tendency is to trust that Police are acting in our best interests... Especially in the absense of something more factual to go off of such as multiple independent witnesses or perhaps even video.
As an aside, the Law Enforcement Review Agency exists to take accounts of alleged misconduct. They are able to independently investigate, help sort fact from fiction and seek appropriate resolution where necessary. The direct link is:
http://www.gov.mb.ca/justice/lera/