“ The plain import of this amendment was to vest a deputy commissioner with broad discretion to correct mistakes of fact, whether demonstrated by wholly new evidence, cumulative evidence, or merely further reflection on the evidence initially submitted.
Nor does our construction 'render meaningless the provision (of § 21 of the Act, 33 U.S.C. § 921) that (a compensation) order becomes final unless proceedings for review are brought within thirty days.' Case v. ”

“ Calbeck, 304 F.2d 198, 201 (CA5 1962) . The review authorized by § 21 is limited to the legal validity of the award; a district court may set aside an award only if it is 'not in accordance with law.' Section 21 (b) , 33 U.S.C. § 921 (b) . ”