Ok, to answer your question, I listened to the radio show where it was read (by the very kind Lyn Gerry). Chapter 3. <http://ftp.radio4all.net/pub/archive/12.22.03/ug179-hour2mix.mp3>
Here are the examples of "crashers," non-professionals who successfully posed as having credentials:
* Daniel Morgan, (career criminal who previously served time in
San Quentin, Folsom, Jackson, Marquette prisons).
Became trial lawyer in Chicago, then arrested for contempt of
court. Reopened for business as personal injury lawyer in
Washington DC (used name of Lawrence A. Harris) for personal
injury. Exposed after he rejected settlement by other personal
injury lawyers. In both cases, apparently had unusually good
record.
* Bob Harris CBS meterologist (then NYT and Long Island
Railroad). Anonymous letter blew his cover.
<http://www.zoominfo.com/people/Harris_Bob_253092348.aspx>
* Barry Allen Vanocker (spelling?). If I understood correctly,
other doctors were offended by him using "MD" on some paper,
then outed him.
* Busting of Pedro de Masonis, fake cert seller, which led to
investigations of:
** Anonymous, described by hospital administrator as
"brightest resident we had."
** Raymond Allard, Barbara Gillen. According to NYT, hospital
staff were unanimous in praise for the two.
There's other interesting stuff in the book I found when reskimming... he used jury duty to cover non-professionals temporarily becoming professionals, and what that entails. Also, touched lightly on the biases of the NYT vs Wall St. Journal (since NYT has a 3:2 professional:manager readership ratio, while the WSJ has a 1:3 professional:manager).
Later in the book, I believe he mentions professional training's similarity with eight "subordinating themes" used in cult indoctrination. (Such as promising to reinvent a "new you", an appealing identity of self-actualized person doing supremely important work.)
(I hope I didn't make too many errors here; listening to audio is slower than reading. But Lyn Gerry did an incredible job reading it; my friend said her voice sounded very soothing and impressive.)
Tayssir