Any server used by many users is, in fact, a production server. If you were just going to mess up your own area on the development server, you wouldn't have felt it was important to mention the other users.
Any outage will inconvenience more than one service customer. In your case, the customers are developers, so they both understand that sometimes things get broken, and that you should have known better.
Your co-workers should not give you any slack for that, either.
What about the original story said it wasn't in his local area on the dev server? Just because he asked his co-workers for advice doesn't imply he ran the script in a public area.
As for slack, I think his co-workers should cut him some, in case they make a mistake of similar magnitude at a later point in time. But in this case, I think it's neither here nor there, since he avoided the outage anyway.