The controller was talking to Frontier plane when he first said stop, then said stopstopTruck1stopstopstop and it would be easy for there to be a gap in processing for the driver of truck 1 because the verbiage all flowed in the same stanza that was started when addressing the Frontier flight.
Every other truck in the column immediately stopped when the call was made. Truck 1 was the only one that didn't.
I am afraid the fire truck might have some level of responsibility, since it seems FAA ground vehicle guidance says:
AC No: 150/5210-20A - "Subject: Ground Vehicle Operations to include Taxiing or Towing an Aircraft on Airports"
https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
“you must ensure that you look both ways down the runway to visually acquire aircraft landing or departing even if you have a clearance to cross.”
These trucks seem to have pretty good visibility from inside. Not sure if La Guardia model was the same: https://youtu.be/rfILwYo3sXc