You can't for the life of you figure out why they "just" didn't set out the bad car, put the train back together and go?
Are you aware of what that entails? I suspect not but let's give you some things you may want to consider. What is the speed of a train with a hot box? How far did they have to go to set out the car with box? What is the shoving speed for the return movement on CSX territory? Where was 90 by the time all of this worked out? When is 80's crew on duty and how much time did they have left by the time this all started and would they have enough time to shove back, assemble the train quicker that it would have taken for 90's crew to make the return movement?
That's the stuff you have to mull when you make these sort of decisions.
Yes, I am aware. The bad order had to be moved to a switch somewhere to set it out. You imply that perhaps the decision was made to drop the rest of the train somewhere, go somewhere else to set out the bad order, and then retrieve the rest of the train. Do any regulations prohibit moving the whole train at restricted speed to the place where the hotbox will be set out? If not, why not do that, set out the hotbox, reassemble the train and go? Yes, recrew if you have to.
The way this was described, it sounds as if the rear of 80 was dropped somewhere for 90 to pick up, while the head end of 80 went further on to set off the hotbox. Doesn't make sense.
jb