At least in the US you can call your local animal control and either them, or the regional wildlife rehab center will help separate them if possible.
Source: Worked at one of those centers in a past life when I wanted to be in veterinary sciences. (SOooOO MANY BABY BIRDS -_- )
To be perfectly honest, I imagine the US government would see it as too big of a risk to just let him go without at least some sort of shadow watching and following his every move, ready to pounce the second he sneezes wrong. This would be if they were to let him leave.
Granted, it would all be speculation, but the possibility does exist.