You can also get a   for the following:
Code:
Original: <p>"Are you talking to me?" Snearing, he replied, "of course I am talking to you! Is there any other?"</p>
Editing: <p>"Are you talking to me?" [Return]Snearing, he replied, "of course I am talking to you! Is there any other?"</p>
Result: <p>"Are you talking to me?" </p>
<p>Snearing, he replied, "of course I am talking to you! Is there any other?"</p>
Note that when Editing, the placement of the cursor is moot except for determining whether the previous (before space) or next (after space) paragraph has the   added. If that space is highlighted/selected and the [Return] is pressed, no   results.
The ebook I'm editing has blank lines between paragraphs in code view (but not book view) in case that matters.
I'm assuming this book was also put through calibre at some point, although I don't know the extent. It lists calibre in it's metadata, but the text itself seems otherwise very clean of the hodge-podge of formatting styles that used to result. It's been awhile since I did any editing though (calibre v8, Sigil v5) and perhaps the conversion output has been cleaned up since then.