WordPress Customizer sanitize_callback: How to Reset to Default on Fail

I check the sanity of some settings with sanitize_callback. It works, but on fail, I want to reset the value do the default one. How can I do that?

$wp_customize->add_setting(
    $attribute[0],
    array(
        "default" => $attribute[1],
        "sanitize_callback" => $validate_func,
    )
);

EDIT

An example for $validate_func is kb_validate_url_facebook which checks if the setting is an URL and if it contains facebook.com.

function kb_validate_url( $url, $valid, $default ) {
    if ( $url === "" ) return $default;

    $url = strtolower( esc_url_raw( $url ) );
    if ( !strpos( $url, $valid ) ) {
        if ( $url !== "" ) {
            return null;
        }
    }
    return $url;
}

function kb_validate_url_facebook( $url ) {
    return kb_validate_url( $url, 'facebook.com', 'www.facebook.com/USERNAME' );
}

In the sanitize_callback function you can look at the second argument which is the WP_Customize_Setting instance and access the default property there when returning due to an empty provided value:

add_action( 'customize_register', function( WP_Customize_Manager $wp_customize ) {
    $wp_customize->add_setting( 'facebook_url', array(
        'default' => 'https://www.facebook.com/USERNAME',
        'sanitize_callback' => function( $url, $setting ) {
            if ( empty( $url ) ) {
                return $setting->default; // <===== Accessing default value.
            }

            $url = strtolower( esc_url_raw( $url ) );
            $host = wp_parse_url( $url, PHP_URL_HOST );
            if ( ! preg_match( '/^(www\.)?facebook\.com$/', $host ) ) {
                return new WP_Error( 'invalid_url', __( 'Invalid URL or not one for Facebook', 'kb' ) );
            }
            return $url;
        },
    ) );
} );