The operation wouldn't have been in jeopardy if the gun had been planted, at seat 10B, by a member of the ground crew.
This is a surprising bit of news, but I seriously doubt if WND reported the entire story. There's a reason why the FAA totally discounts this report, and the reason can't be classified or even sensitive. But now that WND has printed half the story, it's incumbent for the FAA and AA to respond to it, perhaps in another publication.
Why would it even matter if it were true? If I'm not mistaken, Congress has already passed legislation awarding compensation to the victims and precluding their families from suing the airlines anyway.