This was the first time I used this tool, so I was careful to go through the little “tutorial”. I selected my changes on the left, and I *thought* I had pasted it over my comment on the right, but it ended up getting posted twice. But the edit-conflict directions themselves got pasted onto the talk page! It took about 3 more edits for me to completely clean it up.
Topic on Help talk:Paragraph-based Edit Conflict Interface
Sorry to hear that! We are currently working on a completely new version of the extension. This will hopefully avoid such problems in the future.