And in conclusion...

A civil suit filed by a family alleging that benzene in an old San Antonio landfill caused their daughter to develop leukemia may have have implications in drunk driving prosecutions in Texas. The family won a judgment against the city based largely on the testimony of oncologist Dr. Mahendar Patel who testified the child's cancer was the result of her mother's exposure to benzene while pregnant.

Dr. Patel based his opinion on the testimony of the family's other expert witness and on several studies of cancer rates in workers exposed to benzene. He testified that he had never conducted any research on the cancer-causing effects of benzene. The studies upon which he relied were based on workers' exposure to concentrations of benzene more than 200 times the concentration found in the family's yard.

The city claimed Dr. Patel's testimony was conclusory and legally insufficient to support a judgment in several motions for directed verdict after the plaintiffs had rested their case, after the city rested and again after the verdict was rendered (motion for judgment n.o.v.). The city never objected to the admission of the evidence while Dr. Patel testified.

On appeal, the Texas Supreme Court held that a party may complain on appeal that conclusory expert testimony is insufficient to support a judgment even if the party did not object to the admission of the testimony at trial. However, if the objection is that the basis for the expert opinion is unreliable, the failure to object at trial is fatal.

Bare, baseless opinions will not support a judgment even if there is no objection to their admission in evidence. -- City of San Antonio v. Pollock, 284 SW3d 809, 816 (Tex.2009).

The Court went on to say that:

even when some basis is offered for an opinion, if that basis does not, on its face, support the opinion, the opinion is still conclusory. -- 284 SW3d at 817.

The implications for DWI defense are quite clear. If the state's expert offers a conclusory opinion, you have not waived the issue for appeal by failing to object at trial.

Take retrograde extrapolation as an example. The state's expert will take the stand and testify what the defendant's alcohol concentration would have been at the time of driving based solely on a breath or blood test result and the bastardization of the Widmark equation. The state's expert doesn't know what the defendant had to drink, when the defendant drank it, over what period of time the defendant drank it, what the defendant had in her stomach at the time she drank it, what the defendant's weight is, what the defendant's blood-breath partition ratio is or whether the test results are accurate.

The state's expert's opinion may have some basis behind it -- but does that basis support the opinion? In reality, all the state's expert has done was take the breath test result and add .015 for every hour that elapsed between the time of the stop and the time of the breath test. The entire basis for his opinion is the breath test result and he cannot prove that the result was accurate.

A faulty opinion, I conclude.