Technically speaking, the PDFs are bootleg,
Most anything you find on the internet through a search engine may often be of hazy provenance.
That said, I am under the impression from a couple of the authors that both books were released as PDFs, along with several other books in the PH library from that series. I was given a number of them as PDFs by their editors at PH, although I have never shared the ones I received, as I was never told that I could. That said, I did an Internet search for these URLs, and Arnold offers wise counsel.