I wouldn't bother with going to Immigration Office in Philippines direct - chat to the Foreign and Commonwealth Office first
And more importantly don't forget you have to pay to leave the Philippines at the airport
750 pesos
They will not imprison him for not paying visa fees - they have enough problems convicting real criminals accept when the greased palms are involved....
As I said I overstayed 3 months and was not bothered by the local immigration or police