Jack Mills, who was 58 at the time of robbery, never fully recovered from his injuries, and never returned to work. In 1970 he died of
leukemia [1] which an
inquest confirmed, perhaps unsurprisingly, was unrelated to his injuries. As an innocent victim in such an infamous crime, he is very often mentioned when the subject is raised in the press.
http://en.wikipedia.org/wiki/Jack_Mills_(train_driver)