intox indictment with b.a.c. of 0.000

i was arrested for intox charges, but my blood test came back 11 days after and yet this texas county north of dallas indicted me some 3/4 months later and it went almost to the trial date before the judge dismissed it. i know they can do anything they want, but how can the d.a.'s office pursue this charge? of course, now i cannot expunge because it never went to trial. just cost me my life savings and the county a chunk of change as well. they tried lesser charges but jury said no. with no restitution it sure seems unfair. malicious prosecution suit would just cost time and more money...appreciate your time and any thoughts you may reply with. corporate america's greed and power trip is making its way to those who had ideals of protect and serve. thanks