In Magento there are the generic error reports under /errors. These are currently getting indexed by Google. I tried adding the meta noindex tag to the /default/page.phtml but this did not seem to work. Perhaps I should even be touching these files. In other instances, such as with the wishlist, I updated the XML - but can't work out how to do it in this instance. Thanks in advance for any assistance.
Put the following into your robots.txt in the website root:
User-agent: *
Disallow: /errors/
Also here is a more thorough version if you are interested: