I would assume (yeah I know.. don't start) that this sort of meet would have to be set up before 216 even got to Chama. It would take at least an hour to cut the helper out and air test (and set up the retainers) on a long train. It only took 1:05 for 216 to climb the hill. The closest agency west of Chama would have been Lumberton (or Monero?). They could OS the train to Alamosa who could set up the meet.
I'l love to see a train sheet, train order, or register that shows this sort of thing. The few registers I have seen show freights running at night or after the passenger went through.