THE quick “not guilty” verdict reached Tuesday afternoon by a Brooklyn jury in the federal criminal trial of two former Bear Stearns hedge fund managers was at once surprising — for its failure to comport with the zeitgeist — but also entirely understandable, based on a close reading of the prosecution’s arguments and the evidence the judge allowed to be introduced. “There was a reasonable doubt on every charge,” one juror told The Times afterward. “We just didn’t feel that the case had been proven.”

In short, the prosecution blew it — on two counts. First, in devising the original indictment for conspiracy and securities fraud against the two defendants, Ralph Cioffi and Matthew Tannin, it relied on damning snippets...