See earlier bug for description of symptoms and background: How did the [html+php] tag come to exist and how can we make it die?.
This question created the tag
Please do not edit the question just yet, lest you destroy evidence. Yes, it needs improvement and could possibly need closing as Too Localized, but let's not worry about that right now.
You will note that the user has one rep. One rep.
How did this user without the ability to create tags not just create a tag, but create a bogus tag?