edit: How did they manage to drag this out for 5 years and still not have an actual judge or jury rule on this.
Reading through the history of the case[1], it looks like the District Court ruled that the Federal TSA officers involved were entitled to qualified immunity under the Federal Tort Claims Act. The reasoning was that the TSA followed appropriated procedures and wasn't responsible for the longer (few hour) detention by the Philly Police. In my opinion, that seems reasonable. The TSA only detained him for 15-30 mins to question him about the cards, then turned him over the the state police.
After that ruling, the parties settled. I'm not sure why the case wasn't pursued further against the Philly Police. It could be that the case wasn't likely to succeed under Pennsylvania law, or maybe the ACLU wasn't interested in continuing to pursue it, since a Pennsylvania precedent wouldn't be a "worthwhile" expenditure of ACLU resources.
This rings true to me. The TSA in general does not want people in custody. They know themselves that most of what they do is bullshit, so what would be the point? When I was delayed by TSA, they were eager to turn me over to LVPD, who, after a short conversation about the best way to deal with TSA bureaucracy and escape with minimal fines, told me, "if you run you can still catch your plane". Which I did.
Author of TFA had the misfortune to deal with local police just as stupid as TSA, but without the built-in CYA aversion to arrests.
Accountability for what, exactly? He wasn't arrested. He was detained. Police have wide latitude to detain people that are suspicious. I think any objective human being would say that a second look at him was warranted with those items in his bag. Whether he meant to or not, he pretty closely matched the profile of a radicalized US citizen.
BTW, the title of this article isn't even accurate - he wasn't arrested - but then I guess "I was detained for a few hours because I raised several red flags at the airport" probably wouldn't make it to the front page of HN.
Second, how are the TSA agents stopping people from leaving until local PD arrives, if not by making arrests? The moment of arrest is "determined by whether a reasonable person under the circumstances would believe he was not free to leave. United States v. Mendenhall, 446 U.S. 544 (1980)
By contrast, an arrest may only be performed by a peace officer with probable cause to believe a crime has occurred. Detained suspects do not have to have their rights read to them, whereas they must be read to arrested individuals. Detained suspects are either arrested or released usually within hours, as was the case here.
Detention and arrest are vastly different things, both legally and practically, that are used for different purposes. The system worked here: he walked into an airport displaying many red flags. He was detained for a few hours, determined not to be a threat, and was released.