"19 Decisions of the Commission are subject to a privative clause precluding challenge by way of review, quashing or calling into question, otherwise than as provided by the Workplace Injury Act itself: s 350.
In accordance with established authority, that provision would not preclude challenge for jurisdictional error as it does not protect a purported, but invalid, decision: see Plaintiff S157/2002 v The Commonwealth  HCA 2; 211 CLR 476.
"However, the appeal provided under s 353, in point of law, is a sufficient basis for challenge for legal error and no further reference to review under s 69 is required."
from Basten JA in Tan v National Australia Bank Ltd  NSWCA 198. Basten JA, Bell JA simply agreeing, & Young CJ in Eq agreeing in separate reasons. 21.08.08.