I guess they learned the time tested rule to stop and walk the train over crossings that have not been cleaned and oked by the MofW in advance.
They were under "restricted speed rules".
The real question is how long did they take to back up and back over that crossing and re-rail? Back in the early NG days (lighter engines), a crew finding themselves out in the pasture, could put it in reverse and roll on the ice tread they built back to the iron rails.
I hope they didn't damage that plow which was doing such great work. I guess the photographer was heart-sunk too, that his chasing adventure ended.