Now you are showing how little you know. Unlike normal citizens, who are charged and have to prove their innocence in court, the police have a crown and judge review the evidence and if they feel there is not a strong likelihood of a conviction they don't proceed with charges. Now ask me how I know that. I tried to get a couple of cops charged with assault with a weapon (their car) after they hit me with a side mirror while trying to avoid me identifying them so I could complain about their actions. I had to write out a statement describing the event, go down to College Park to swear in front of a JP to the event, and then show up another day to be questioned by a Crown and Judge. At the end they decided there wasn't a high chance of conviction so they didn't bother charging them. I did get a written apology and the ticket they gave me was withdrawn but still, another example of police not being treated like normal people. If one of your neighbors called and said you hit them with your car and drove off, would you be charged???
As you pointed out, this happened 9 months ago and there are likely no real witnesses to what happened, and even if there were they likely can't provide a credible identification of two men that were only seen for a short time so far in the past. As there are not going to be credible witnesses, and it is unlikely they have video evidence, the crown probably made the determination that they wouldn't get a conviction which is why they are only facing disciplinary action.
But please, keep trying to defend the obvious criminal actions that these 'good guys' engaged in. It looks good on you.