I don't really understand it. Why look out glasses had to be locked up?, why wasn't a little cabin in crow nest where to keep the binoculars?, was it a tradition or an obligation to keep them in other part of the ship? as far as I know, Blair is guilty, Fleet and his companion in the nest could have seen the iceberg "something draker than the night itself" with a proper pair of binoculars. Blair must have been comdemned with Ismay for the rest of his life in prision.