I don't see how bungling equates to "handling with kid gloves." The prosecution committed an egregious violation of basic legal tenets (the Sixth Amemdment to the U.S. Constitution, specifically) by charging Leung using testimony from a source it then attempted to shield from cross-examination and possible impeachment. If Leung is guilty, the government can arrange for the sequestration of classified information during the testimony. Anyone who has a problem with a defendant being allowed to be confronted by a witness and to cross-examine that witness is basically arguing for a kangaroo court.
I am against shady dealings by prosecutors in any way, even in espianoge cases.
Most of these types of cases would result in a conviction anyway, so it is better to play it straight.