Had a similar thing happen to me at JFK of all places last week. Ran through airport to get to my commuter flight at B31. Got to the gate 10 minutes before push and of course door closed and Agent finishing up at her terminal. I walked and said “so door is already closed?” She said “yep” without even looking up. So as I am walking across terminal to the lounge for my 4 hour sit until the next flight, while muttering “F..ing New York” I hear behind me “sir, sir”. I turn around and the gate agent says “they have maintenance on board and so I can get you down the jet bridge while they finish up”. WOW! She quickly listed me for the jumpseat on the full flight even though I had been listed non rev. Another WOW! Anyway thanks to her. Renews my faith in humanity.