[Tim Wood]

Originally Posted by patp

For some reason, when I try to select multiple items in the right hand pane using the Apple key or the Shift key, I can't click on the name of the entry itself. If I do, it simply edits the entry and deselects my previous selection. On the other hand, if I click on the arrow to expand the entry or if I click on the icon (the envelope) then it does select multiple items as I intended. However, in the left hand pane I can click anywhere on the entry to select multiple items.

Is this intentional or is this a bug?

This is a bug, though it is true that OmniOutliner has the same bug. Since you've held down a modifier flag, we should really treat the click as a row selection operation. We've logged this, bug make sure to use Help > Send Feedback to mention that it's bugging you so we can prioritize it correctly.