Most courts have interpreted the scope of that immunity broadly.
She said there could be a legal challenge to narrow the scope of the immunity.
But Judge Pollak, in his ruling, said that "eBay's role does not extend beyond the scope of federal immunity".
Yet, the UK government would – in expanding the 'act of state' doctrine and the scope of state immunity – seek to enshrine it in common law.
And in any event, he said, it is up to the courts, not the executive branch, to determine the scope of its immunity in particular cases.
A police source said the attorney general's rushed clarification "made a nonsense" of the original announcement of the scope of the immunity made by Lord Cullen, who chairs the inquiry which formally opened last month.
Although Judge Leasure sharply limited the scope of the immunity agreement earlier, prosecutors still had to demonstrate that their witnesses and evidence were not derived from or tainted by knowledge of Mr. Starr's findings.
Solicitor-Advocate Simon McKay, who is acting for the families of Cpl Aston, Cpl Keys and Cpl Miller, said: "The claims follow a recent Supreme Court ruling extending the reach of the European Convention on Human Rights (ECHR) to some theatres of war and the scope of combat immunity as a defence available to the Ministry of Defence".
"The process of whittling away the scope of the immunity available to protect the participants in judicial processes appears to be far from over", she said.
One barrister, Clare Montgomery QC, looked at the implications for other participants in the legal process, commenting that the "process of whittling away the scope of the immunity" that they have "appears to be far from over".
