Update: This paragraph is a test to see if I can reproduce it. italic ... Yep, confirmed.
Solution: "Enforce proper nesting of HTML" in Display Settings. D'oh!
The node 11115734 contains an unclosed <i> in the "EDIT" at the top. However, the HTML for this node differs depending on whether I am logged in vs. logged out. When logged in, it's
<p>
<b>EDIT:</b>
<br />
I <strike>use</strike> <i>used</i> bareword filehandles.
<i>In the course of this discussion I was convinced not to do so.<i>
</i></i></p>
But when logged out, it's
<p>
<b>EDIT:</b>
<br />
I <strike>use</strike> <i>used</i> bareword filehandles.
<i>In the course of this discussion I was convinced not to do so.<i>
</p>
What's going on? Of course the "fix" is to correct the unclosed <i>, but I'm surprised at the rendering difference.