In the UK it often takes much longer than a week to get all the details,
and sometimes flight tests are undertaken after that to investigate various
issues, before the full analysis can be completed. There is then often a
review process by certain interested parties before a final report can be
published.

One example of delays is in finding the log book(s) of the pilot(s) to
ascertain recency and experience etc. There are many other things sometimes
required.

Admittedly, a year seems a very long time, but months is far from unusual,
in my limited experience of having been involved in a few.

Chris N.