Well, I have not had any of these bugs, but there have been several reports on foreign visitors that have been cloned by glitches. Maybe this is one of those times?
In any case, since it's obviously a bug or glitch, it may be very hard to know whether Chen dies when he gets home or if he's survived his own death (
only in the Sims). Therefore, you should be careful about sending him back, at least make sure to save before. My experience from this game gives me a hunch that glitch or no glitch, he's going to be a normal sim when he moves in with you (as the Grim Reaper for example becomes), so he may be just fine, but as said; just be careful about it.