I need to verify this a little bit but I was trying to document the Case Sessions rights.  First of all there's a right that's called which seems to do nothing.  There's another right that says which covers the display button.

Then I am not exactly sure what's going on here but I was trying to figure out what would cover the "List" right for listing Sessions, Documents, and Case Comments. First I tried and I took away basically all the rights except for , and I could still see the Sessions, Documents, and Comments, and I even had the available buttons (display, edit, etc) but when I clicked on them they told me I didn't have the rights.  But then like 10 minutes later I checked again and I didn't have any access at all.  It was really weird.  Like I said I need to verify, but I can state with certainty that the rights governing stuff in the case management module aren't exactly logical.

I tested this out in 4.0.57.32, demo site.