The weight of expertise

Personalised evaluation and judicial standardisation, 2015

The creation of a unified DES legal dispute that was more than the sum of its individual lawsuits did not, however, guarantee that victims would be appropriately compensated. The recognition that laboratories had failed to perform their duty of vigilance and therefore that they were liable did not exempt victims from providing evidence of harm in the context of defective product law. In order to do this, victims must prove their exposure to DES, as well as the existence of a causal link between this drug and the harm suffered, and then mobilise the legal regulations that require the laboratory that manufactured the drug to provide compensation. If the judge deems the evidence admissible, s/he must then determine the amount of compensation to be awarded. In a civil case, all of these elements are theoretically treated individually, on a case-by-case basis. In practice, however, several legal mechanisms have been used to standardise the treatment of both victims and damages.

From the very first case brought to trial, the question of medical causality has been raised, always in the context of the general appraisal conducted in 1994, where the difference between legal evidence and scientific evidence was clearly defined by the experts:

“There is a clear discrepancy between the term ‘undisputed cause’ and the usual biological and medical reality. It is incredibly rare for us to be able to answer the question with an absolute ‘yes’ or ‘no’”.

One after another, judges have broken with this concept of scientific uncertainty, asserting that there was a “relevant probability of the causal role of Distilbène®” in the appearance of clear-cell adenocarcinoma. Moreover, judges have seen T-shaped uteri as a “signature pathology”: identifying this malformation and the damages linked to it as establishing a form of causality that could systematically be attributed to DES. At the same time, however, for victims suffering from other pathologies, individual expert medical opinions are always decisive: in fact, the panel of experts, generally composed of three individuals, is tasked with determining the reality of victims’ afflictions, as well as the causal link, if any, with DES. Expert reports are an important “strategic resource” for the different parties involved. They involve lengthy clashes between victims and pharmaceutical companies regarding how to choose experts, and who should pay them, as well as the quality of the reports and the need to conduct further inquiries. Héloïse says:

“These expert assessments, they’re terrible because you have to relive everything you went through and believe me, they know how to make you experience the worst all over again.”

An analysis of dozens of expert reports illustrates the variety of rulings issued, due to the multifactorial nature of the different afflictions reported by DES daughters. Nonetheless, here again judges have reduced these differences to the process of establishing a certain and direct causal link, in particular by discarding alternative causalities and refusing to accept a probabilistic model. Although judges are not tied to experts’ conclusions, they must not change the nature of expert reports: they therefore select elements of the report to either confirm or reject a causal link for each and every affliction. This Boolean model of legal causality once again serves to unify victims, by treating different individual pathologies and uncertain and fragmented scientific knowledge in a similar fashion.

Expert assessments also help to certify that victims were truly exposed to the drug. In fact, even if a causal link with the damages have been established, it is still necessary to identify which laboratory manufactured the drug prescribed in order to force the company to provide compensation. Although the first victims to come forward were in possession of a prescription proving they had been exposed to DES, in many later cases, victims did not have this kind of evidence. Several decades after the original prescription, many victims are unable to produce any documentation identifying a specific laboratory.

Court of Cassation judges once again transformed the law in 2009, when they ruled that once the causal link between a pathology and exposure to DES had been established, “it was the responsibility of each laboratory to prove that its product was not the cause of the pathology”. With this ruling, the judges in fact reversed the burden of proof in the victims’ favour. In the absence of documentation identifying which of the companies manufactured the drug that gave rise to the harm in question, liability for said harm fell in full to each company. Consequently, proof of exposure was thus partially based on the existence of signature pathologies and, when these were absent, on solid and consistent evidence (medical files, testimonies).

While expert appraisals are always a lengthy and arduous process for victims, the evolution of case law means that the legal framework for accepting their complaints has expanded.

Pharmaceutical companies have come to constitute a unified party, which strengthens focus on their liability. It therefore falls to each individual company to provide evidence that it is not the liable party. In a similar fashion, judges have further helped to unify victims, regardless of the laboratory responsible for their damages and, more importantly, regardless of the documents proving exposure that they possessed.


  • Abstract from “From Individual Redress to the Development of a Collective Cause: The Legal Mobilisation of Victims of DES”, Revue française de science politique (English Edition), Pages 583 – 607, 2015/4.
  • Image credit hellorf.

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