If MB was refusing to pay RG for unpermitted renovations that RG snd LK thought they were owed $50,000 for, RG would not have had access to the civil courts to recover the money if RG was not a licensed contractor.
If MB was refusing to pay for the work, RG being unlicensed (if true) makes it easy for MB to stiff him, knowing RG cannot use the courts. So RG says, if you’re not paying for the renovations, I’ll report them as unpermitted. If the renovations are in the living space not occupied by LK and RG, they are not ordered to vacate their upstairs apartment, but MB is unable to use the whole house even if LK leaves.
Just speculation, but it explains why RG would call the building inspectors,
Re: treble damages: How is RG going to be assessed treble damages as an “unlicensed contractor” if there is no written “contract” for the renovations? Is he still an “unlicensed contractor” if there is no “contract”? In the absence of a contract, RG could say he was doing it for free (especially since Barisone was maintaining that RG would not be paid) and 3 x zero = zero.
Were the renovations involved in converting the basement to living space? If that was the case, it would need to have provided egress for any basement bedrooms to conform to code regardless of whether the work was done by a licensed or unlicensed contractor.