I think the big leap here for him was seeing live events vs. pre-recorded films. When these predictions were written, silent films would have been commonplace and live radio broadcasts weren't around. News would have been distributed via newspaper, sent world-wide by telegraph.
The phonograph and newspaper were forms of mass reproduced, widely distributed storage though. Most of their media at the time would have been from persistant storage of some form, created once and sold many times over (newspaper, records, player piano rolls, etc).
