TOPIC: Front End Permissions Incorrect?- Bug?

I have a User added to the permissions table so they can access CSV export from front end. They are set up as "Edit Own Event only" - checked. "CSV Export" checked. All other permissions are unchecked including "Edit Events". Despite this they can still edit their events which I do not want.

In my Joomla 1.5 instance of DT Register with this same set of permissions they cannot edit their event, just access the CSV export.

Which is the correct behaviour? The latter seems more sensible to me with the the capacity to edit their own event being provided if required by checking the "Edit Events" checkbox

Edit - I have discovered that ANY user group with access to the Control Panel can access and edit my events despite not having "Edit Events" box checked. The only way to stop this is to check "Edit Own Events only". Surely this is not intended?? If it is, I strongly recommend that documentation on permissions is improved. I couldnt find anything useful about this in PDF or tutorials