How can they? What legal right does the NCAA or the B1G have to ask for that money back? None. They don't have any claim to the $60M either, except via a threat to remove Penn St. from NCAA membership. That would be a dicey proposition if they tried it by the way, since there's not a university in the land that doesn't have some baggage. UConn used to have a high rate of rapes on campus (dark, quiet, insufficient lighting, no call boxes). UConn was pretty obviously negligent in that regard during my time, and only addressed it much later.
I think the NCAA and B1G pushed this about as far as they could without having PSU push back. This is a state institution, and has a plausible claim to sovereign immunity.