Ты не ...
public function deleteRow( event : MouseEvent = null ) : void {
var delEvent : DynamicEvent = new DynamicEvent( "deleteEvent", true );
delEvent.dataToDelete = data;
dispatchEvent( delEvent );
}
тогда в классе с вашим DG ваш DG.
<mx:DataGrid id="foo" dataProvider="{someDP}" />
foo.addEventListener( "deleteEvent", updateDP );
private function updateDP( event : DynamicEvent ) : void {
foo.dataProvider.removeItem( event.dataToDelete );
}