Here are the guidelines of the Sheriff's Oath: "qualifications required for the position of Police Officer; that I will support the Constitution of the United States, the Constitution of the State of Missouri, the provisions of all laws of the State affecting Constitutional Charter cities, and the ordinances of the City". RSMo 57.100 lays out the state guidelines for the office of Sheriff. Now that I've told you all of that, tell me how Sheriff Shannon did not do his job.
My answer would have been, "Am I being detained?" "Am I free to go?"