Did what? It is odd that they waited weeks, but clearly it wouldn't have been a priority. It's not like they hauled her out in irons at 3am to an undisclosed location. Don't burn *censored* in a park. Now if this story had read "woman tazed while burning confederate flag in her backyard", I might be able to summon some outrage. But really my outrage bar has been raised much higher when it comes to abuse of authority, sadly.
Also, this happened in June of last year, and the charges were dropped a few months later. Her notification to police prior to the event indicates that she wanted to get arrested for arson and must have been sorely disappointed when cops had better things to do.