How can the Hadith "The child is for the bed" be reconciled with the case of Li'an, and does the Hadith not constitute a definitive ruling regarding the child's lineage to the husband?

A child is attributed to the husband if born on his marriage bed, unless the husband disowns him through li'an (oath of condemnation). In that case, the child is then attributed to his mother, like a child born of zina (illicit sexual relations). The Prophet, peace and blessings be upon him, said: "The child is for the bed, and for the fornicator is the stone." This means that the child is not attributed to the fornicator. So, a child born of zina is attributed to his mother, and the same applies in the case of li'an and the husband disowning the child.