Thankfully, you were not in charge of the situation; and, hopefully, you never will have the responsibility of determining a terrorist threat.
If this happened on the Fruited Plain, the sequel would be a lawsuit - a quite meritorious one perhaps. Sometimes, once in awhile, a litigious society has its upside.
One other thought. What is the advocated policy here? That Arab looking folks speaking what sounds like Arabic, wearing too much clothing for the weather, and looking at their watches too often, can't fly, no matter how screened? That passenger angst should dictate who flys?