Abscondence from service is also unauthorized absence but with the only difference of the absentee remaining incommunicado in the former.
Coming to the case of the poster, his resignation would have been accepted subject to the condition of serving his notice period of one month. Resignation will take effect only from the date of formal relief of the resignee from his job. It is not just like a resignee can simply walk away after acceptance of his resignation. No bad precedent can justify such an act for the commencement, continuance and conclusion of a contract of employment are matters subject to the conditions already stipulated therein.
It is quite unfortunate that such questions on the legal consequence of sudden resignations skipping the notice conditions are very often raised by exiting employees in this forum. Such people, in my humble opinion, have scanty regard for the rules and regulations of organized employment in general and the administrative difficulties likely to be faced by the employers in particular. When the notice period is such a shorter duration as one month, why not they obtain sufficient joining time from the prospective employer, serve the notice period sincerely and make the separation smooth and peaceful to both? Buy-out is an option only to meet urgent situations like sudden and serious illness of the resignee or other family commitments like marriage that require immediate shifting of the place of residence or personal commitments like joining a course of study. Hence it cannot be insisted as a matter of right.
Being considerate is certainly a very noble and essential quality expected from all in social relationships.