Final report due
The latest official date, officially stated many months ago, was said to be August 2015.
The KNKT chief stated at the time, see my transcript of the interview at the time, that he it was clear to him what had happened.
What has happened does not automatically give an answer as to the Why.
There may also be other reasons for a delay in publication. But not announcing a delay, and hinting at the reason or reasons for a delay, is of course not a recommended practice...