It sounds like he transferred between missions. I'll take a wild guess that when he left his prior mission, they handled it the same way as a missionary going home.
I agree with jdlessley that it's something for the mission office to deal with. If you are the mission office, you should have a support line for things like that. This forum is primarily user-to-user, so unless there is someone here who has worked in a mission office, you're unlikely to get a more detailed answer.
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