No, they are taking an existing law (even if the protestors aren't violating it) and using that to justify their infringement on these people's rights. Who is the judge going to believe? The cop or the protestor? Even if the judge or DA decides the charges aren't warranted, ultimately the protest was stopped. The ends justifies the means? The cops don't want you protesting... they'll find an excuse to shut you down.
When citizens have to prove their innocence in order to exercise their Constitutional rights, what kind of nation does that make us? A free state or a police state?