When a document is updated with second version of the file, the access to the earlier version is disabled and the current version becomes the active file to be accessed. In this instance, if the user had downloaded the original version earlier, the files becomes unavailable and would be prompted with a message that informs the user to re download the updated version.
[* As an administrator, you can always revert back to the earlier version to make it current by clicking on the edit option. You can enter this screen by "right clicking" on the document and selecting "edit".
When this is done, the same logic applies to any files downloaded before the changes were done, the user will need to re download the file]