Groundpounder, I fully agree with your comment on their working conditions.
The airport weather may have cleared, but to the west may have still had thunderstorms, and they deviated through it.
As someone who has had many, many, long days followed by all nights, I sympathize with their possible condition. Old guys? I did a 17 hour 'day' in a power plant, dealing with high voltage at close, exposed distances. I drove an hour and a half to get back home, arriving at 5 AM. On my 70th birthday. I fully understand that the level of competency and alertness can degrade rapidly under those conditions.
Young guys get caught in the same trap, a co worker died at 6 AM, on his way home. He had been working since 7
:30 the previous day.
If those guys had not slept well during the previous day, they were in a fatigue hole that is hard to dig out of.