app/code/community/Aoe/TemplateHints/Model/Observer.php
public function showHints() {
        if (is_null($this->showHints)) {
            $this->showHints = false;
            if (Mage::helper('core')->isDevAllowed()) {
                if (Mage::getSingleton('core/cookie')->get('ath') || Mage::app()->getRequest()->get('ath')) {
                    $this->showHints = true;
                }
            }
        }
        return $this->showHints;
    }
public function showHints() {
        if (is_null($this->showHints)) {
            $this->showHints = false;
            if (Mage::helper('core')->isDevAllowed()) {
                if (Mage::getSingleton('core/cookie')->get('ath') || Mage::app()->getRequest()->get('ath')) {
                    $this->showHints = true;
                }
            }
        }
        return $this->showHints;
    }
Check if hints should be displayed

@return bool