Wouldn't it be Lindh's lawyers more likely to leak these? they've been playing to the press from day one.
From the CNN article:
In March, the government turned over the e-mails to U.S. District Judge T.S. Ellis. He ruled that they did not have to be shared with the defense.
At a June 17 hearing, Ellis expressed concern that the e-mails had been leaked to the media and wanted to know how that had happened. He gave the government three weeks to file a response and take appropriate action. Ellis stated in open court that the e-mails had been "ruled 'privileged' and were not to be produced."
So they were only in the hands of the prosecution and judge, as I read it.
Perhaps pointing fingers at Clinton-holdover 5th columnists inside the DOJ is more appropriate.