As a former District Attorney and former City Attorney they likely tried to bring in the blood without the phlebotomist. They are usually indep contractors who move on from the job often. So, subpoening them for trial is an issue. They likely "found" her, meaning they put forth more effort in locating her than the normal assembly line sub system. The age of the case helps you.
Good luck with your case.
Assuming that the prosecution cannot lay a proper foundation for the admission of the blood test results, the officer can still testify about his observations - your driving at the time of the stop, the field sobriety tests, the objective symptoms of alcohol consumption, and other factors such that a jury could convict on "under the influence" section [VC 23152(a)), as opposed to the ".08 or over" section [VC 23152(b)] on which you could not be convicted without proof of blood alcohol.. My guess is that the appellate court found error, among other things, in dismissing that "(a)" count (unless there was insufficient evidence to support a conviction on that count as well). Of course, depending on the facts of your case, you have a much better chance of an acquittal if the prosecution cannot present evidence of what your blood alcohol level was at the time.
Your best bet is to try to have a detailed conversation with your public defender. Failing that, you should seriously consider consulting with a few private dui attorneys in a confidential environment, which this site is not. Good luck.
A roundup of the best tips and legal advice.