Could you just accept the fact that there may be a good reason that would possibly be private? Here are some reasons why foreign-born priests have been repatriated in my memory. Of course these things could apply to any domestic priest - its just that maybe the local Bishop has enough on his hands and doesn't need more trouble:

one was exposed a falling-down drunk
One seduced a married woman
One seduced a kid
One was raising money ostensibly for an orphanage in his home country and it was really going to his illicit wife and children
One was raising money for a private project in contravention to AoD rules about how/why collections can be taken
One was actually politically-active in ultra-right wing movement

Maybe the case in discussion was none of these things. Maybe something else. Maybe more nefarious. Maybe less.

But seems like something there.