The Mage_Core_Controller_Varien_Exception::prepareRedirect method has been broken since the class was introduced in 1.3.2 (Current: 1.9.1.0) https://github.com/OpenMage/magento-mirror/blob/1.9.1.0/app/code/core/Mage/Core/Controller/Varien/Exception.php#L67-L72

broken-exception-prepareRedirect.patch

Index: app/code/core/Mage/Core/Controller/Varien/Exception.php
===================================================================
--- app/code/core/Mage/Core/Controller/Varien/Exception.php	(revision )
+++ app/code/core/Mage/Core/Controller/Varien/Exception.php	(revision )
@@ -67,7 +67,7 @@
     public function prepareRedirect($path, $arguments = array())
     {
         $this->_resultCallback = self::RESULT_REDIRECT;
-        $this->_resultCallbackParams($path, $arguments);
+        $this->_resultCallbackParams = array($path, $arguments);
         return $this;
     }