Paul, I have seen a few different interviews with Alfred White, and I don't really know exactly how he escaped. In one interview he hints at being one of those picked up by boat 4, in others it is difficult to tell what he means. He said he was in a lifeboat which was quite full and there were five firemen in this boat. My, admittedly far-fetched, theory is that he might have been one of the many firemen/trimmers in boat 15. On the other hand, he may well have been the eighth, hitherto unknown, person picked up by boat 4.
Best regards,
Peter