What’s the big deal? He just described the airport terminal in Chicago.
If an incoming flight had a bris, are the outgoing flights exempt from Tachnun? What about if they arrive after you left? Does it depend on where they get their meals? Would it make a difference if the airline is based over there? Which one?
What if, by saying Tachnun you’ll be putting your head down on a wall, over which there is being a Bris? Do you first put your head down and get up, or keep it there, or make believe it happened and skip it?