Is it still unknown what actually happened to Thomas? Was he detained, but then not booked? So “arrested”, but only by a thin technicality and not what people commonly think of as “arrested”?
EDIT: Any chance at all it was a “Let’s get you out of here, Mr. Thomas!” ride in the squad car and not a true suspect arrest?
I don’t think Underhill would be saying he was arrested if he wasn’t. But, there seems to be a chance he was never booked, so who knows. People that originally broke the news before anyone said he was released over 8 hours ago.