Judgments and orders passed by an Appellate Court upon an appeal shall be final, except in the cases provided for in section 418, section 419, sub-section (4) of section 425 or Chapter XXXII:
Provided that notwithstanding the final disposal of an appeal against conviction in any case, the Appellate Court may hear and dispose of, on the merits,-
(a) an appeal against acquittal under section 419, arising out of the same case; or
(b) an appeal for the enhancement of sentence under section 418, arising out of the same case.
