These "news" get amusing with a new twist each & every time with something different, as in "no kidding."
The next headline to pop could be - "holiday traveler's carry-on items triggered another false alarm as it turned out to be a small box of Ferrero Rocher, hazelnut chocolates with creamy fillings"

wrapped in gold tin foils, apparently not "TSA certified as clear to fly .... " as being suspicious, LOL.
As for AA Gate Agent(s), don't they usually "page" the passengers via overhead PA's inside the terminal and near the boarding gate area - since they usually do a final headcount and sometimes re-seat some of the pax to better balance the plane's load. But had they done that & decided to hold the plane at the gate for a few extra minutes - it would ruin their on-time departure statistics ....
Meanwhile, the real would-be bad guys are singing & dancing in joy, realizing the terrorism impact of our security theater.