Whilst attempting to reproduce #309784: Unordered lists override numbered lists, I entered the following HTML into the node body, with Full HTML filter set.
<ul>
<li>A. Item</li>
<ol>
<li>Sub-item 1</li>
<li>Sub-item 2</li>
</ol>
<li>B. Item</li>
</ul>"Correct faulty and chopped off HTML" was enabled. The resulting output on my node view was
<ul>
<li>A. Item</li>
</ul>
<ol>
<li>Sub-item 1</li>
<li>Sub-item 2</li>
</ol>
<li>B. Item</li>When I disabled "Correct faulty and chopped off HTML", the output was the same as the input.