The US Department of Defence suffered another damaging leak this week when NBC learnt the government’s chief suspect in the WikiLeaks case could not be tied to Julian Assange by its own investigation.

The leaking of the confidential findings — now surely to be part of Private Bradley Manning’s defence — sparked a tense exchange during today’s Pentagon press briefing between chief spokesman Geoff Morrell and NBC chief Pentagon reporter Jim Miklaszewski, who broke the story.

That investigation had intended to find evidence of a conspiracy between Manning and Assange, giving the US a crime to seek extradition of the WikiLeaks founder. The lack of a link does not let Manning off the hook, however, as the Pentagon claims it already has evidence he downloaded the documents to his personal computer, which is itself illegal.

“This is a very broad, very robust investigation that will look any and every place to find all those who may or may not have been involved in the leak of this classified information,” Morrell told the briefing.

The spokesman also snapped at other reporters who asked whether the investigation would prevent further leaks through WikiLeaks, telling them to “go ask Assange or one of his cronies”.

But Morrell could not fend off questions about 23-year-old Manning’s treatment at Quantico Marine Corps base near Washington DC. The Pentagon has only refuted a handful of the allegations made by Manning’s lawyer David Coombs and supporters who visited Manning.

Brig Commander James Averhart is alleged to have arbitrarily placed Manning on suicide watch last week, against the advice of two psychiatrists. That involves removing his glasses and all clothing bar his underwear, except during his allotted one-hour recreation time.

Coombs noted this was in addition to the 243 days in confinement, isolated and with 23-hour lockdowns each day.

Averhart was replaced as brig commander today by with Chief Warrant Officer Denise Barnes. The Pentagon denied the move was linked to the media interest in Manning’s treatment, that Averhart had exceeding his authority or that an investigation had been launched into the suicide watch decision. It also denied mistreatment of any kind.

Morrell insisted Manning was being held in conditions consistent with any other solider being held at Quantico, which is officially intended for short-term detainees awaiting trial no more than 90 days.

“He is in a cell by himself, but that is like every single other pre-trial detainee at the brig. It just so happens that the configuration of the brig is that every individual is confined to his or her own cell.”

Unrelated but simultaneously, Manning’s primary visitor was held by military police, questioned, searched and had his vehicle towed when he turned up for a pre-arranged visit on Sunday accompanied by a blogger. 

David House and Jane Hamsher were held until the moment visiting hours ended. More than an hour into their detention, House tweeted: “MPs looking for a reason to arrest us; brass arrives. The US government is like any animal: scare it and it will try to tear your face off.”

The Pentagon is yet to answer questions relating to that incident.

State of the Union

Meanwhile, yesterday’s State of the Union proved a much lighter affair for a nation still mourning the dead in Tucson’s shooting, but was first overshadowed by law makers’ “dates” and then by pitted olives.

President Barack Obama’s address delivered exactly what he had earlier promised: reinvigorating modern job-growth industries and a modest rethink on government spending.

The address is traditionally also a call to American greatness — a signature Obama forte — but lines such as “win the future”, “do big things” and “become a teacher; your country needs you” fell short of his best. Not that the Republican responses did much better. The Washington Post even called the Tea Party response “Michelle Bachmann’s alternative universe”.

Utterly uncaptivated by the address itself, American media and blogs went straight for the gossip and intrigue of what might become a new tradition: Congressional Date Night. Audiences were treated with close ups of law makers introducing their opposite-party “date” to the president as he made his rounds of handshaking.

The new practice of sitting intermingled rather than strictly divided along party lines was in honour of shooting victim Rep Gabrielle Giffords. But so eager were some law makers to sit near the empty chair reserved for Giffords that some “dates” of Arizona delegation members were stood up and had to find alternative seats further away from the cameras.

When the excitement of prom-esque gossip wore off, newsrooms and reporters twitter feeds discovered America’s version of the Australian parliament’s stroganoff incident.

Rep Dennis Kucinich has filed a lawsuit against the House of Representatives cafeteria because the olives in his lunch were not pitted properly. The congressman is seeking $150,000 damages “for future dental and medical expenses and to compensate him for pain, suffering, and loss of enjoyment”.

Kucinich’s “date” for State of the Union was eccentric Republican Ron Paul. No word on whether they went dutch for the unpitted olives.