I walked off a DC-10 in 1999 in Harare Zimbabwe.
Captain wanted to fly an unsafe and unairworthy jet. Flight engineer backed him up. I used all the CRM tricks I had to no avail, so I said, "I'll make this easy for you. Call the chief pilot and tell him I'm refusing to fly the aircraft." Then I got my bags and went back to the van.
These things occur, still.