I KNOW how many downloads there were. Since it was a PDF the download is automatic.
How did the author discover it?
Someone else informed him of the link from Google.
Your personal space does not have a password protection?
No password protection on the site. It is open to the public. Folks got to the book directly from Google.
I would take the position that the stats are inconclusive as to what accounted for them. That’s legit.
Scripts and bots can replicate human behavior. DON’T assume that all your hits/downloads were done by humans who found your personal page out of the zillions of pages on the internet. Don’t rely on the download weblog stat to crucify yourself. “The search engines index web pages, text files, and other “human readable” files. Images and other such files are ignored. But the engine does read Adobe PDF files and will return search results for these.”
Here’s an interesting article...
http://www.divorcekit.com/Google/Googlebot_Wont_Go_Home.html
(see the part about reading pdf to the end)
If it’s possible that the downloads weren’t done by people, then what was the damage? The content is not there now so even if the search results across the planet point to your page, it’s a broken link. Document the dates you published the content, the date you removed the content so subsequent appearances of the link on search engines are irrelevant. Make sure Google removes the cache version and any other you become aware of.