If he is already selling to a large processor , then chances are , he has a license to sell raw milk as a licensed dairy farm , as far as I know , it's the processors who pasteurize milk not the producers.
Not sure about laws in your state , but where I am , you must be a licensed buyer to buy from a producer , you must be licensed by the milk marketing board and have an established quota for buying raw milk.
Making and selling cheese is pretty much strictly regulated in any part of north America.