Anybody can start a sports card grading company, not regulated or insurance required for grading error, but insurance most likely needed for theft etc when in their possession. So the card grading companies can make there own rules and its only their opinion what the grade is. Just remember a card just money on paper and is only worth what someone is willing to pay whether slabbed or raw at that time, Also it always come down to doing your research and if not sure about the card walk away.