More likely, the Justice Dept wanted to hold up the indictment until after the release of the 9/11 report so as not to be accused of trying to influence their findings.
Berger knew that the indictment would come down soon after the release of the report this week. He gave a heads-up to Kerry who freaked out because he didn't want the story breaking during his national convention, so he either leaked it himself or told Berger to leak it immediately.
The timing of the leak seems awfully suspicious. It would be to the Republicans advantage to have the story break at the time of indictment next week.
I agree with your take on this,completely.