Good Samaritan Arrested for Help

I cant help but find this to be the most ridiculous charges that I have ever seen someone be arrested for. A New Jersey woman who was walking by the scene of an accident where a woman was hit by a van was asked by the police if she spoke Spanish. They needed her to speak Spanish so that they could communicate with one of the parties in the accident, the woman agreed to help them and was acting as an interpreter for them. Moments later she was arrested, placed in handcuffs and put in the back of a squad car. The charges that she was arrested under stemmed from the fact that she was being "uncooperative" and was arrested for obstruction of justice and resisting arrest. Now resisting arrest is a bogus charge police use all the time and has very flimsy pretenses for using. I really don't understand how she can be arrested fro obstruction of justice for being uncooperative. She entered into the arrangement as a good samartin who would attempt to offer her services to interpret the Spanish being spoken for the officers. At any point should she feel she doesn't want to do this anymore she can walk away she isn't bound by anything to continue helping. Therefore how can she become uncooperative? She isn't part of the accident she isn't a witness she is a passerby who was trying to help and was arrested on what appear to be some bogus charges. For the link to the article and video of the event check out this link.