The evidentiary value of private expert opinions is very close to that of court expert opinions. In practice, this is often not the case: many courts tend to regard private expert opinions, i.e. expert opinions commissioned outside the proceedings, as a nuisance. These expert opinions, which are usually “labeled” as biased, are therefore in most cases considered to be of lesser value than court-commissioned expert opinions and are downgraded in the judgment with clichéd justifications. However, this approach, which is widespread in practice, is not covered by supreme court case law! In fact, expert opinions provided by the parties are important for the constitutionally guaranteed legal protection of the parties. This is the only way to fully uncover – not infrequent – errors in court reports.