My friend sent be back an email (after checking with his sister who is the hunter and food preparer!):
My sister said to bake the pig in the oven
low heat (300-325) for an hour then put on BBQ pit and
make a sauce with onion, little bit of vinegar, mustard, sugar, stick of butter
and salt/pepper and baste it while BBQ---the baking slow cooks it throughout and
the bbq gives it the smokey taste and crisps the outside...
u can also do the baking then BBQ and use a sauce of ready made BBQ sauce and honey
and apply at the end of the BBQ process