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.
...the TSA... wasn't responsible for the longer (few hour) detention by the Philly Police.
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.
The TSA "officers" do not have arrest power and are forbidden by policy from using force (to perhaps perform a citizens arrest if allowed in state for a state law violation), so they really don't have the ability to take anyone into "custody", hence calling for local police.
The reason why they don't have arrest powers is because splitting up the particular duties involved in infringing liberties makes it impossible to pin it on anyone. The TSA can blame it on the locals, the locals can blame it on the TSA, and 9 times out of 10 they don't even need to find a patsy for a scapegoat.
(IANAL) The thing is the ACLU only has leverage against the Federal gov't if they pursue a settlement - the federal gov't doesn't want to see the agents deposed. Even if they have immunity, it'd make them look bad. If this went to trial, that leverage would be gone. So, the settlement deal gets them point 2 on that list, instead of just (potentially more) money.
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.
[1]: https://www.aclu.org/national-security/george-v-tsa