Running into I had a look at the implementation of ListStore's addAll method. I was a bit surprised to find that in case the store is filtered the StoreAddEvent is only thrown on those items that were added AND comply with the filter rules. That is, all items are correctly added to the store, but not all new items are given to the event object but only those that comply with the filters.
Although for rendering purposes this may be indeed exactly what one wants, for anybody trying to keep track of newly added items to the store this makes life really difficult.

My suggestion is that, if it is really necessary to distinguish for the StoreAddEvent between the filtered and unfiltered case, to add both collections the actual list as well as the filtered list to the event.

- acer