In Zend_Form and Zend_Form_Element there is possibility to turn off translator with method setDisableTranslator(). My propose is to add such a functionality to method Zend_Validate_Abstract::getTranslator like in below code

    public function getTranslator()
    {
        if ($this->translatorIsDisabled()) {
            return null;
        }

        if (null === $this->_translator) {
            return self::getDefaultTranslator();
        }

        return $this->_translator;
    }

By default translator could be enabled but when you disable translation in Zend_Form_Element it will be disabled in validator also.