I'd like to hear the other side of this story. Human trafficking is essentially fatal to its victims. Some false positives are the price of mitigating it. There should be ways to reduce false positives, but these methods need to be kept secret from the traffickers and therefore from the public.

Lawyers making a case like to pretend that perfection is attainable or at least the objective. It's not. If you aim for 100% accuracy you are most assuredly accepting a large type 1 or type 2 error rate.

Southwest could be completely in the wrong in this case. But if this case results in airlines letting more human traffickers escape detection that's a disservice to victims.