Just now, I lost some text that I had input due to an edit conflict after a page move on enwiki. Here's what happened:

1. I edited Talk:New York University Polytechnic School of Engineering to comment on an edit request there.
2. While writing my comment, I moved New York University Polytechnic School of Engineering to New York University Tandon School of Engineering to answer the edit request. I checked the options to move the associated talk page, and to move subpages of the talk page. The page was semi-protected and had full move protection.
3. I edited New York University Tandon School of Engineering to update the DEFAULTSORT. (Though I doubt this step is relevant.)
4. I then finished the comment on Talk:New York University Polytechnic School of Engineering and saved the page.

This resulted in an edit conflict screen, and both the edit window and the "Your text" box contained the content of the redirect page. The comment I had been typing was lost.

While I suspect that this is a general bug in MediaWiki, I couldn't reproduce it by following similar steps on testwiki.