He may have been cooperating with one of the secret Chinese “police stations”. What are the chances that they weren’t told where they were going?
I think he either sent somebody back, as you say, or possibly a spy.
Those Chinese secret police stations....were mostly there to monitor ex-Chinese folks who’d walked out of China. I would imagine surveillance/phone monitoring was going on, but we will never get to that part of the story.
I wonder if it was someone who previously escaped China, and was being sent back, to face a firing squad? Maybe it dawned on the guy, when all the flight attendants were speaking Chinese. What a miserable flight that would be.
China would at least give them jobs, working alongside the Uyghurs.