add_table() help within views_query_alter()

Hi, so I'm trying to add the term_node table to a view within views_query_alter(). If I add a taxonomy Term TID within the Views UI, the $query structure includes 'type' => INNER for the term_node table. Whereas when I programmatically add the table with add_table() the 'type' is set to LEFT. I'm out of ideas...

Example outputs below:

$query output after adding Term TID filter via views UI:

views_query Object
(
    [table_queue] => Array
        (
            [node] => Array
                (
                    [alias] => node
                    [table] => node
                    [relationship] => node
                    [join] => 
                )
            [uc_product_stock] => Array
                (
                    [table] => uc_product_stock
                    [num] => 1
                    [alias] => uc_product_stock
                    [join] => views_join Object
                        (
                            [definition] => Array
                                (
                                    [left_field] => nid
                                    [field] => nid
                                    [table] => uc_product_stock
                                    [left_table] => node
                                )
                            [extra_type] => AND
                            [table] => uc_product_stock
                            [left_table] => node
                            [left_field] => nid
                            [field] => nid
                            [type] => LEFT
                            [adjusted] => 1
                        )
                    [relationship] => node
                )
            [node_data_field_preorder] => Array
                (
                    [table] => node_data_field_preorder
                    [num] => 1
                    [alias] => node_data_field_preorder
                    [join] => views_join Object
                        (
                            [definition] => Array
                                (
                                    [table] => content_type_product
                                    [left_field] => vid
                                    [field] => vid
                                    [left_table] => node
                                )
                            [extra_type] => AND
                            [table] => content_type_product
                            [left_table] => node
                            [left_field] => vid
                            [field] => vid
                            [type] => LEFT
                            [adjusted] => 1
                        )
                    [relationship] => node
                )
            [node_counter] => Array
                (
                    [table] => node_counter
                    [num] => 1
                    [alias] => node_counter
                    [join] => views_join Object
                        (
                            [definition] => Array
                                (
                                    [left_field] => nid
                                    [field] => nid
                                    [table] => node_counter
                                    [left_table] => node
                                )
                            [extra_type] => AND
                            [table] => node_counter
                            [left_table] => node
                            [left_field] => nid
                            [field] => nid
                            [type] => LEFT
                            [adjusted] => 1
                        )
                    [relationship] => node
                )
            [term_node] => Array
                (
                    [table] => term_node
                    [num] => 1
                    [alias] => term_node
                    [join] => views_join Object
                        (
                            [definition] => Array
                                (
                                    [left_field] => vid
                                    [field] => vid
                                    [table] => term_node
                                    [left_table] => node
                                )
                            [extra_type] => AND
                            [table] => term_node
                            [left_table] => node
                            [left_field] => vid
                            [field] => vid
                            [type] => INNER////// - desired value
                            [adjusted] => 1
                        )
                    [relationship] => node
                )
        )//... more stuff here

And if I programmatically add the table within views_query_alter() with:

$view->query->add_table('term_node');

I get the same thing other than 'type' => LEFT:

[term_node] => Array
                (
                    [table] => term_node
                    [num] => 1
                    [alias] => term_node
                    [join] => views_join Object
                        (
                            [definition] => Array
                                (
                                    [left_field] => vid
                                    [field] => vid
                                    [table] => term_node
                                    [left_table] => node
                                )
                            [extra_type] => AND
                            [table] => term_node
                            [left_table] => node
                            [left_field] => vid
                            [field] => vid
                            [type] => LEFT/////// I can't see how to make this INNER
                            [adjusted] => 1
                        )
                    [relationship] => node
                )

Any help much appreciated. There's not much information about this in the API or online.