Sham software reference not enough: Judge stays on in Mercedes emissions case

A panel of judges of the tasked with hearing challenges (wrakingskamer) of the Amsterdam District Court recently rendered a judgment on the challenge (wraking) of a judge in a collective action against Mercedes (ECLI:NL:RBAMS:2025:2609). The challenged judge is president of the three-judge division that handles the case in question. Mercedes claimed that the presiding judge was biased in an earlier publication about collective actions by referring to their case in the same context as the scandal about Volkswagen’s use of illegal software. The decision clarifies when legal commentary crosses the line into alleged bias.

Challenge of a judge

One of the fundamental values of the judiciary is impartiality, which means that a judge must be neutral until judgment is rendered. If one of the parties gets the impression that a judge is biased, the party can ask to have the judge replaced by another. This can be the case, for example, when the judge says something that indicates bias. This request to have a judge replaced is called a challenge. The mere appearance of bias is sufficient to challenge a judge. This does not necessarily mean that the judge is actually biased. If the judge disagrees with the challenge, the matter is reviewed by a panel of three other judges specifically tasked with hearing challenges.

Collective action against Mercedes

In 2020, Stichting Diesel Emissions Justice and Stichting Car Claim initiated a collective action against Mercedes and its partners regarding diesel vehicles produced and imported by Mercedes and sold by its partners. According to SDEJ and Car Claim, the vehicles are equipped with a prohibited manipulating device that would make them non-compliant with the applicable emission standards, Euro 5 and Euro 6. SDEJ and Car Claim are acting on behalf of the buyers and lessees of the vehicles in question. The foundations seek, among other things, an annulment of the agreements between injured parties and the car dealers and compensation for damages. In the main action, Mercedes requested a pre-trial hearing, this request was denied.

The court’s decision

The challenge is based on the following. In a legal publication on class actions in the financial sector, the judge wrote a chapter on mass litigation from the perspective of the judiciary (hereafter: the publication). In that publication, the judge wrote, among other things, about requests for an unnecessary pre-trial hearing which are sometimes used as a delaying technique, referring to the applicant's case. The judge also speaks of “sham software” (sjoemelsoftware). According to Mercedes, this suggests that this is indeed the case, while Mercedes explicitly denies this. According to Mercedes, with these two passages, the judge showed bias, or at least created the appearance of bias.

By way of defense, the judge explained that if the case against the applicant is referred to in an article that deals with collective actions in the financial sector as “a case about sham software,” this obviously does not mean that the examining judge already considers it proven that the applicant used sham software. According to the judge, this is simply the common designation of this type of case. The fact that the publication mentions that requesting a pre-trial hearing can be a delaying tactic, does not mean that it is said that the applicant has used this tactic or that this impression has been created.

Judges are generally discouraged in various codes of conduct from commenting publicly on cases on which a judicial (final) decision has yet to be given. According to the codes of conduct, it is not desirable for a judge to write articles about judgments of his or her own court or to comment on them publicly. However, it does not follow from this that a judge is not at all allowed to comment on matters that are going on in his court or that are being handled by him or her, but it does follow that a judge should be cautious and considerate when making those (non-substantive) statements.

In the opinion of panel of judges hearing the challenge, the (subjective) bias experienced by the applicant is not objectively justified. According to the panel, the term “sham software” has evolved over time from the scandal surrounding Volkswagen's use of the software in question to a more general term referring to the use of manipulative instruments and/or software (illegal or otherwise) in order to gain some advantage (intentionally or unintentionally) when measuring results.  Therefore, it cannot be deduced from the quoted passages that by using the term “sham software” the court is drawing conclusions or anticipating any (final) decision to be taken in this case. Nor can it be inferred from the quoted passages that the judge considered that the idea behind the pre-trial hearing requested by the applicants was to cause delay. The judge merely referred to the applicants' proceedings factually and in an observant matter, without commenting substantively, to illustrate cases in which no pre-trial hearing was stipulated. In doing so, the judge did not state or suggest that the request for a pre-trial hearing involved delaying tactics on the part of the applicant. The panel therefore dismissed the challenge.

Key takeaway

This ruling emphasizes that objective impartiality is the key standard in challenges. Merely citing a judge’s general or academic remarks – even if those comments touch on issues related to an ongoing case – will not suffice unless they clearly indicate bias or prejudgment. This leaves room for judges to participate in academic or legal discussions, even on topics relevant to cases they are handling, as long as they avoid making substantive or biased statements – an approach we endorse. 

Co-author Cato van den Berg