WebDesigner question regarding "bulk operations"

Hi,

I would like to ask a question regarding the data event handler "Insert/delete bulk operation". (v8.1.4)

To my understanding, this is only fired once per insert/delete action, not once per object. However it does not seem to work as expected, as it seems to fire once per object in my scenario.

I added an event Handler in VI_ITShop_Shoppingcart for Insert/delete bulk operation on ShoppingCartItem.
I would like to execute the shopping cart checks when someone removes one or more items from the cart, through any means.
However, it seems the checks are executed once for every deleted SCI when the whole cart is deleted ("Delete7" Node: Delete database object and save), for example.

What am I missing?