Sir Alan Moses, who presided over the Soham murders trial, faced criticism over the role of the new Independent Press Standards Organisation (Ipso).
Hacked Off, the campaign group demanding statutory press regulation, was due to take part in Monday night's debate Edinburgh Napier University but pulled out at the last minute.
In a statement it claimed Ipso, which is replacing the Press Complaints Commission, was no more than a "fake regulator".
The group said: "Hacked Off sees Ipso for what it is, an outright rejection of the Leveson Report. The Leveson report was the product of a 15-month public inquiry into press regulation and was - via a Royal Charter - overwhelmingly endorsed in the Westminster Parliament and endorsed in the Scottish Parliament."
Following yesterday's court verdicts, Brian Cathcart, of Hacked Off, said Rupert Murdoch's UK newspapers should now abandon their plans - with other newspapers and magazines - to establish Ipso and sign up to the Royal Charter agreed by the three main political parties.
"For years the Murdoch press clung to the story that one rogue reporter was responsible for phone hacking. We now know this was a lie. Far from being an isolated incident involving a few 'bad apples', the trial has shown that the entire orchard was rotten," he said.
"The trial also shone a light on the appalling, systemic newsroom culture of bullying, lies, intimidation and intrusion that has devastated the lives of many people. From royalty and Cabinet ministers to victims of crime and bereaved families, nobody was safe."
Sir Alan declined to comment on the hacking case. However, he has vowed to make himself an unpopular figure in the industry, suggesting this would be proof the new set-up is working. News UK said that they had put in place measures to ensure that the wrongdoing could not happen again.