The escaping issue has [been mentioned](http://stackapps.com/a/2381/9371) already, but I'd just like to accentuate it with a screenshot - 

><img src="https://i.sstatic.net/wIKNA.png" width="440">

As you can see, the HTML is actually being rendered. In the case of an HTML comment, the content is simply not displayed, but HTML content here is being showed as an un-ordered list item.

[Here](http://stackoverflow.com/questions/13108749/blur-entire-li-except-last-word) is a link to the post from the screenshot.