The news report seems a little confused which isn't unusual.
On the general issue of anonymous posting, if you write a letter to a newspaper they will publish it under a pseudonym but insist on knowing the sender's real identity as well. I have no problem with telling a reputable discussion board my name and address as long as I they are not displayed to the general public. Nor do I have a problem with them revealing it upon due legal process.
Making a board owner liable as "primary publisher" if s/he fails to take action over a defamatory post seems perfectly reasonable.