"Did he stay with them all night and the rest of the crew took the ride back to Antonito?"
Yes, Lopez stayed all night.
There is a notation" Willis & ? into Antonito 9:00 AM and tied up 9:30 AM Feb 10." It would appear they rode with the 477 when it left train 426 after pulling draw bar off engine 470, around 8:30-8:45 AM