Being under steam made for some interesting positions of workers under the engine. I suspect there were a few minor burns.
It was a 'push', not a 'pull'. A 'pull' would have been awkward as there was no way line up couplers.
Since 497 had a train attached, and it would have required some fancy manouvering to unattach the train, the whole thing was shoved back. I doubt if #19 could have done it. In any case, 489 was dispatched from Cumbres as soon as the incident was reported, so sufficient motive power was there.