Yes, it occurred it that example page, as well. These are the steps I am taking:

1. Copy a line of text from anywhere. 
2. Paste it into Notepad.
3. Copy the line out of Notepad.
4. Place your cursor in the editor, and then Paste in the copied text (CTRL + V).

After going through these steps, when selecting the "HTML" view from the bottom of the editor, the text is surrounded by div tags.

I recently updated to 3.6.14, and the issue is still occurring.