“Given that an insured person’s treating practitioner must provide a factually based medical opinion to support a claim for treatment outside the MIG, I find it is reasonable to require an insurer who chooses to refuse to pay an initial claim to counter with something more than simply a desire ‘to determine if your impairment is predominantly a minor injury as described in the Minor Injury Guideline,’ as Unifund has done in this case,” Sapin wrote.