Actually, if you look at the comment in the news report about the back propellor coming off, there are various ways of reading this.
Did the tail rotor come off due to some mechanical problem, or did it come off as a result of impacting the trees?
There is little in the news report that says sufficient to warrant no investigation.
However, there is a difference between an investigation and a prosecution for dangerous flying. Why waste the time of good investigators if the pilot has admitted to a gross error by failing to recognise the conditions that caused the accident - eg. proximity and height of the trees surrounding the landing site etc.
The flight apppears to have been operated under the private category, although I may be proven wrong here of course. Therefore, it is unlikely that much will be done in terms of punishment for the pilot, other than what he has already suffered.
iceberglead, you say that you are accident/incident free cos you treat flying very seriously. I think that you'll find that most of the members on this site treat flying very seriously, but many, like me, have experienced some form of accident or incident as a result of something that they were not fully aware of. As far as I am concerned, flying is a continuous learning process, but sometimes the lessons can be very hard!