I personally think that tasers should not be used by police, or anyone for that matter. The fact that they are thought of as a 'less than lethal' weapon, yet have killed thousands of people. The user has it in thier mind that the taser is non-lethal, so will use it as such. Fact is, human bodies are not designed to take that kind of electrical shock, and occasionally people die from a taser.
That woman obviously needed some "persuasion" to put her hands behind her back, and I believe the officer had the right to use a non-lethal weapon. But I personally hate tasers, and I would have probably pepper sprayed her, or called for back-up and used physical force.
(Cop did the right thing, but it's the system's flaw for issuing him the taser, and making it an acceptable weapon.)