[vorpalhex]

Your critera excludes most of the NRC.

The court does not need to build a nuclear reactor. They need someone who can help the court understand nuclear.

Your theoretical person may be a bad choice if they have no communication skills.

[heavenlyblue]

They certainly are a bad choice if they are not actually an expert though

[karmakurtisaani]

Let's be honest here: both sides of the case want "their" expert to testify. I.e., someone who has enough knowledge on the topic to push the given narrative convincingly. There is a massive difference between a court case and actual science.