Allen & Overy has failed in its attempt to prevent documents it released by mistake being used by its opponents in long-running litigation.
Mr Justice Lindsay last month refused to grant Allen & Overy an injunction on the use of four attendance notes which the firm had sent by mistake to seven defendants of a claim by its client News International.
News International is suing a former director, Michael Clinger, for allegedly overcharging its subsidiary News Datacom by £19m for supplying Sky "smart cards" which allow viewers to receive satellite TV signals.
It is also suing five other individuals and seven offshore companies which it alleges were involved in a conspiracy against it.
Last month Judge Lindsay heard how a trainee at Allen & Overy had mistakenly faxed four attendance notes dating from 1995 to a company defendant, three individual defendants who are all litigants in person, and to Paisner & Co, which is acting for Michael Clinger.
The trainee had been asked by partner Judith Gill to check on the computer whether the documents had already been disclosed to the defendants.
When the trainee found they had not, she assumed that Gill wanted her to fax them to them as she had with previous documents.
When Gill realised the mistake she phoned Paisners and faxed the three litigants in person, telling them that the documents were privileged and should be returned and that no use should be made of them. All of the parties refused.
Allen & Overy then applied to court for an injunction against the use of the notes and instructed Jonathan Davies-Jones, of 3 Verulam Buildings, as counsel.
But Judge Lindsay held that the "reasonable solicitor" would not have realised that the notes were disclosed by mistake. Only if a "reasonable solicitor" could have realised this would the documents retain privilege, he said. He added that litigants in person would be even less likely to realise that the notes had been sent in error.
The litigants in person had read the documents before Gill had asked them not to, so privilege would be lost for them, ruled the judge.
Further, he agreed with Paisners' counsel, Thomas Beazley, of 2 Hare Court, that it would be impractical to make the documents privileged only for Paisners' clients and not for the litigants in person.
So he waived privilege for all defendants and ordered Allen & Overy to pay their costs.