(ShareCast News) - Shares in Churchill Mining slipped despite the company providing an optimistic update on its arbitration case against the Government of Indonesia, whose key witness failed to attend.The AIM-listed company brought the hearing against the Indonesian government to protest against what it felt was an unlawful revocation of Churchill's 75%-owned East Kutai Coal Project, on which it has spent $67m on exploration and feasibility studies to define a 3.1bn tonne resource.The hearing has been completed, with fact witnesses, oral presentations and expert witnesses all provided as expected, except former East Kutai regent Isran Noor, one of the government's key witnesses.Churchill's chairman David Quinlivan said the board was pleased the hearing had largely been completed, save for the presentation of post-hearing briefs by both sides."Overall, the hearing was a useful exercise but it is disappointing that Mr Noor, one of Indonesia's key witnesses, chose not to attend the hearing, as we had a number of questions we wished to put to him. We look forward to having this aspect of the case decided so we can move ahead with having our merits claims determined."The company's broker, Northland Capital Partners, said Noor's non-attendance was a surprising development but that the hearing was progressing in line with its timing expectations.It noted that Churchill's damages have been independently assessed at $1.3bn.Shares in the company fell as low as 30.25p on Friday before bouncing to 35p, a 7.8% fall, by 1300 BST.