It seems that after the derailment, Mr. Murphy took the rest of the day off.
Imagine this:
The Pineapple was above the train;
The Frieght Special was above with 3 cars on the end;
The derailment happened early in the day;
The train was where you could drive right up to it with tools, lights, food, etc.;
There was plenty of room to work, unlike MP 310;
It was warm, and it didn't rain;
The crews knew exactly what to do and how to do it, and did it right the first time;
There was good radio reception, unlike some other places on the line.