Not sure that I get your point? Since it appears that one cannot cast an AGAINST vote, I assume that what you are saying is that if NW would have cast his 25,915,937 shares these could then have been added to the 9,017,855 votes Withheld, for a total of 34,933,792 Withheld. The Total Votes cast (assuming no other changes) would have been 51,340,822 + 25,915,937 = 77,256,759. In this scenario, LP would still have 42,304,837 FOR votes, which would represent 54.8%.
What would NW accomplish by voting? Likely would not be able to swing the votes sufficiently to get her booted out? And even if he hypothetically could, that would destroy the Share Price. And if he votes against LP then this would be seen as a vote of no confidence by him, so again this could hurt the Share Price badly. So "why bother" voting? He would not accomplish anything, and likely do harm to his position.