The article does not say the big mouth passenger was arrested or detained in compliance with FAA guidelines. It was the pilot's call on behalf of the airline he did not cite any FAA standards. If other passengers were alarmed or aware of the comment, he had to address it. The article does state that the pilot and crew were tested using FAA procedure.
The crew reported to a medical facility to be tested for alcohol and drugs, in compliance with Federal Aviation Administration guidelines.
This is the only mention of FAA standards and does not relate to the (almost)passenger.
Sorry, I should have been more clear. I took the FAA comment, along with the following, to mean there's a possible violation of federal law:
The FBI and the U.S. attorney's office will discuss the incident after the holidays and decide whether the man should face the more serious charge of interfering with a flight crew, a federal felony that carries a maximum 20-year prison term, said Monica Shipley, FBI spokeswoman.
Regardless, the airline industry is now virtually an extension of the federal government. The idea that government agents can act under the same guidelines as a private security guard is clearly erroneous.