There is several possibilities here. 1) There could've been an arrest warrant out for the guy for something he did back home, 2) They found drugs in his bags or person,3) He did something wrong at one of the ports of call.
But for as parking tickets ? No ! What ever went down, it was serious for them to arrest him there.
In 2001, @ New Orleans terminal, we got to see the drug dog in action. As we where going into the luggage terminal,from the ship. The drug dog was standing at the corner of the walkway, by his patrol officer., and all of a sudden the dog started barking, and tring to corner a guy a few feet in front of us.. Then they escorted all of them away.