Would this information not be in the contract to begin with? If not, then the author has nothing to pay, publisher can send all the bills they want and scream till they go blue in the face. If it is however in the contract, then unfortunately it's on the author to read these more thoroughly before signing. Maybe some don't realise this, but signing a book contract is just as big a deal as signing with a record label. You don't just plop your signature at the bottom and cross your fingers.