I've just tested that structure on my site and it doesn't redirect.
The problem your experiencing, I think, is due to 'canonical redirection' which exists to help improve your site's SEO (debatable :) ). Since several urls can point to the same content (including 'incorrect' ones) - WordPress redirects the user to the correct or 'canonical' url. This on its own shouldn't cause the issue.
EO doesn't interfere with that process - but other plug-ins may do. And since it seems to work on my test install, it suggests this may be the case.
I would first visit your Permalink > Settings page and click 'save' a few times - just to ensure the rewrite rules are properly flushed.
If that doesn't solve it, try uninstall all plug-ins/theme and flushing the permalinks again. If a plug-in/theme is causing the issue that will highlight it.
Typically though, there shouldn't be a problem - WordPress handles the permalinks for your posts and the post type event.