the Board’s use of Zamora on the issue of involuntary withdrawal. Compared to Pittman, the Board now insisted that the claimant bear the burden in the first instance of proving not only the circumstances of his retirement, but also whether he was simply unwilling to continue working. The Board also adopted a “something-less-than-American Axle” standard that confounded practitioners insofar as the Board simply stated that the claimant had to make a showing of a post-retirement job search, but how genuine that search needed to be was left open-ended.