They definitely bungled it, I have no idea what the training is for that area. In Canada it would of been handled differently I'd imagine.
I wouldn't say this is Cowboy attitude and abuse of authority... this situation looks 100% of people who were either not trained properly or completely f'd up and made a panic decision. Cowboy authority would of had them beating the guy to a pulp before he even had a chance to walk to the van.
Why shoot him that many times, most police are trained to shoot to stop the immediate threat. Their has been times (not sure about in Winnipeg)