The point about an expert witness is that they are the only people who are allowed to give an opinion in a trial, but they're not allowed to present new evidence. The idea being that you submit your evidence, and then get an expert witness to present an expert opinion on it. If you don't have admissible evidence, you don't have anything to give an expert opinion on, and the judge concludes you don't have a case.
And make no mistake: you did not have a case.