Fix comments; switch to watching nodes

pkg/controller/framework/controller.go

@@ -115,7 +115,9 @@ func (c *Controller) processLoop() {
 //      get called even if nothing changed. This is useful for periodically
 //      evaluating or syncing something.
 //  * OnDelete will get the final state of the item if it is known, otherwise
-//      it will get an object of type cache.DeletedFinalStateUnknown.
+//      it will get an object of type cache.DeletedFinalStateUnknown. This can
+//      happen if the watch is closed and misses the delete event and we don't
+//      notice the deletion until the subsequent re-list.
 type ResourceEventHandler interface {
 	OnAdd(obj interface{})
 	OnUpdate(oldObj, newObj interface{})