Hide Pages on Edit Pages based on Capability (edit_others_pages)?

I was using the wrong query_var. It’s author not post_author.

add_action( 'pre_get_posts', 'wps_admin_exclude_pages' );
function wps_admin_exclude_pages( $query ) {
    if( ! is_admin() )
        return $query;

    global $pagenow, $user_ID;
    if( 'edit.php' == $pagenow && 'page' == get_query_var( 'post_type' ) && ! current_user_can( 'edit_others_pages' ) )
        $query->set( 'author', $user_ID );

    return $query;
}