When you disable the export and a user tries to export data from a view, from the security aspect the application behaves as designed. From the users point of view it looks like Notes does not work correct. There is no hint for the user that the export is disabled for this application. ( unless he takes a look at the application properties, what a user never would do )
So IBM, please either disable the menue option for exporting data when the “Disable Export of view data” is checked or at least show a message box to the user who tries to do an export.