He won't get far. Problem is that he was only momentarily detained and inconvienced. He wasn't arrested, removed from the premises, held, his property confiscated, or really anything. He's got very little as a case.
It appears that from the article he was certainly opressed (temporarily) and intimidated.
USC TITLE 18 > PART I > CHAPTER 13 > Sec. 241:
If two or more persons conspire to injure, oppress, threaten, or intimidate any person in any State, Territory, Commonwealth, Possession, or District in the free exercise or enjoyment of any right or privilege secured to him by the Constitution or laws of the United States, or because of his having so exercised the same; or
If two or more persons go in disguise on the highway, or on the premises of another, with intent to prevent or hinder his free exercise or enjoyment of any right or privilege so secured -
They shall be fined under this title or imprisoned not more than ten years, or both; and if death results from the acts committed in violation of this section or if such acts include kidnapping or an attempt to kidnap, aggravated sexual abuse or an attempt to commit aggravated sexual abuse, or an attempt to kill, they shall be fined under this title or imprisoned for any term of years or for life, or both, or may be sentenced to death
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Note that under federal law, all they have to do it conspire to do so. That also means that the blissninny who called the cops could also be endicted under this statute.