You can subscribe to our status page to be emailed when something goes down, when it is playing up, and when it is fixed. Those emails carried a link to the incident — and the link went to a page that did not exist, so anyone following it landed on a “not found” error at exactly the moment they were trying to find out what was wrong.
Status emails now link to the incident on the status page itself, and the page scrolls to it and highlights it when you arrive. Being straight about the scale of this: nobody is currently subscribed to status alerts, so no customer received a broken link. It was found and fixed before anyone signed up rather than after.