I think the government has an obligation to keep up its promise especially when it deals with a foreign nation. However, this cannot be allowed to intervien in the course of justice. In fact, the government should have obtained the court's prior concurrence to give such a promise.
Other than that , the bombay blasts are nothing but a retaliation act of the demolition of babri masjid and as such things should be viewd in toto and the bombay blast should not be tried as an isolated case.