[lucubratory]

From what I understand the PRC tries pretty hard to provide a lot of incentives to academic returnees. I do wonder if they have a tenure match program, where if you have tenure at an American university of a given calibre you are automatically granted tenure at a Chinese university of a similar calibre if you return to China. They probably should.

[Andrex]

If that's true, then that seems to be the simplest explanation for what happened here? (Honestly asking.)

[lucubratory]

Oh, no. I'm not talking about alleged espionage, I'm talking about people moving universities. Moving university doesn't mean disappearing off the face of the Earth.

[Ar-Curunir]

It is extremely bad form to leave your students stranded and move to another university with no communication. It also wouldn't warrant FBI action; plenty of people have moved back to their home countries from academic positions in the US.