Always use the most outrageous anecdote to get the camel's nose under the tent skirt...
The legal theory on which the judge based his ruling goes back hundreds, perhaps even thousands of years.
The commenter defamed another person, which is actionable in court.
The fact that the commenter was essentially standing in the public square with a hood, or bag, over his head so no one could see who it was that was commenting, shouldn't protect him against legal action.
The judge correctly ruled his anonymity cannot protect him from prosecution for an illegal act.
By way of example, what is the correct decision if the commenter instead robbed a bank though the use of hacking? Should he then be able to keep his anonymity?