Are judges decisions on an expert witnesss qualifications only a matter individual opinion?
In general, court decisions are based on the applicable evidence code. Most states and countries have an evidence code that decides when a court can allow someone to render an opinion in court. When the court allows the evidence, the court does not rule that the person is right or wrong, it just allows the opinion to be considered. The standards in most places are pretty generous. if the person has specialized knowledge, by virtue of training or experience, such that an opinion my be helpful to the trier of fact, then the court should allow the opinion whether the court thinks it is right or wrong.
