There are two potential avenues. One is to apply to the Federal Court for judicial review. The second one is the board's reconsideration process, which is an unlimited right that allows veterans who have been denied benefits at appeal to ask to have the claim reconsidered based upon new evidence, errors of fact, or errors of law, and those tests have been set out by the Federal Court, and they can have unlimited opportunities.
On May 31st, 2016. See this statement in context.