Take everything they tell you with a grain of salt, especially things like "the decision was made and cannot be reversed". It's possible that in the course of i

Take everything they tell you with a grain of salt, especially things like "the decision was made and cannot be reversed". It's possible that in the course of interviewing you they realized that they needed a person with a different set of skills than what they originally thought they needed and so decided to change course with that position. Could be any number of reasons though really.