Dunne wrote his "fictional" novel years ago:
http://www.amazon.com/exec/obidos/tg/detail/-/0345430557/qid=1119763505/sr=8-1/ref=pd_bbs_ur_1/104-8664251-6773559?v=glance&s=books&n=507846
1994; while he was writing it, somebody gave HIM the secret report that Michael Skakel's father had had commissioned, supposedly to prove his sons innocent; when it didn't, Rushton Skakel buried the report -- but somebody sent it to Dunne.
Years later, he gave it to Furhman to investigate; Mark's "discoveries" were in that report. Dunne does give him the credit for doing the leg work......but Mark could have never done it without Dunne's "report."
The person who sent D.Dunne that P.I. investigation team's secret report on the probable identity of Martha Moxley's killer was the young man told to make copies in the Skakel lawyer's office.