Any party in interest may, within twenty days after notice of a referee's award or disallowance of compensation shall have been served upon him, take an appeal to the board on the ground: (1) that the award or disallowance of compensation is not in conformity with the terms of this act, or that the referee committed any other error of law; (2) that the findings of fact and award or disallowance of compensation was unwarranted by sufficient, competent evidence, or was procured by fraud, coercion, or other improper conduct of any party in interest. The board may, upon cause shown, extend the time provided in this article for taking such appeal or for the filing of an answer or other pleading.

In any such appeal the board may disregard the findings of fact of the referee, and may examine the testimony taken before such referee, and if it deem proper may hear other evidence, and may substitute for the findings of the referee such findings of fact as the evidence taken before the referee and the board, as hereinbefore provided, may, in the judgment of the board, require, and may make such disallowance or award of compensation or other order as the facts so founded by it may require.