I agree, but I don't think this obviates the need for regular citizens' videotaping the police. If surveillance is going to be omnipresent, I think it's crucial that regular people are able to present their viewpoints as well.
If we rely solely on the recordings that are produced by the powerful, it seems all too likely that things will be presented out of context, recordings will be 'lost', etc
I would assume (read: hope) that both defense and prosecution would have access to the entire taped incident. And if the taping were lost that the benefit of doubt would go to the civilian, not the officer.
The difference is that if there was supposed to be a video, and the video went missing while in the sole custody of the police, it is a reasonable inference that the video went missing because it supports the defendant's version of events rather than the police version.
Indeed--this is a standard evidentiary rule (and jury instruction) in almost every U.S. jurisdiction. In a criminal case, it would be enough to throw out the case, with prejudice. In a civil case, the judge would even be within his authority to issue a finding of fact against the party that "lost" the video.
If we rely solely on the recordings that are produced by the powerful, it seems all too likely that things will be presented out of context, recordings will be 'lost', etc