Goodbye Keyshawn Hall

[Pablo]

How is he allowed and everyone else was denied?

It depends on the rulings of the courts. Hall lost his case in the Ohio Court of Appeals and, then, sued in New York and was granted a 5th year of eligibility. There are actually several football and basketball players who have been granted a 5th year of eligibility by the courts pertaining to this NCAA rule change that was intended to be prospective.