Tested:

On current 6.2.2-SNAPSHOT

Situation:

• Content app using contentType (here events app using event contentType)
• two types existing: 'event' node and 'mgnl:folder' node (as all apps usually have, folders additional to an custom type)
• 'event' node should be editable (orange)
• 'mgnl:folder' should not be editable (yellow)

Code in the events app:
Realise that it is defined that the editor's availability should react only on the nodeType 'event'.

subApps:
  browser:
    workbench:
      contentViews:
        tree:
          columns:
      
            location:
              expandRatio: 1.0
              filterComponent:
                 $type: textField
              editable: true
              editor:
                availability:
                  nodeTypes: 
                    - event
                field:
                  $type: textField
                  rows: 3

Problem:

When going into edit mode on an 'event' node (orange), it works fine as expected:

When going onto an 'mgnl:folder' node the edit reacts in a wrong way:

• Nothing is editable, which is correct
• Somehow it reacts on a strange way: all is empty (see folder name), as it were editable.
  
• The tab jumps from event to event node and then also to the folder node which is shouldn't.