This is one of those times to remember the NCAA is not the IRS. It’s not a government entity or regulatory agency. It’s just an association of members. It’s the schools who set NCAA policy. The NCAA only enforces it.
So in the case of Terry Henderson, cruelly denied a sixth year at N.C. State in apparent violation of both recent precedent and human decency, the guideline to remember is that these rules are in place for a reason. Schools want to discourage transfers by making players sit out a year (and continue to seek acceptable ways to neuter the grad-transfer rule), so the NCAA enforces the letter of the law.