I would expect an Expert to study on the particulars of a case. In general as long as they are sufficiently narrow I don't see a problem here.
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.
There is a legal "standard" around the admissibility of expert testimony (https://en.wikipedia.org/wiki/Daubert_standard).
The person who got me to testify told me he made around $700 K per year. He drove a ~$200K Maybach so I had no reason to doubt him.
I also met a plaintiff's lawyer who told me, roughly, "If the lawsuit ever sees a jury, the jury never understands the science. It's all about likeability and looking good. I had a juror tell me, 'I picked your side because you had a really nice tie.' So, I always wear a nice tie!"
That was probably a hyperbolic story, but I'm sure there's a lot of truth to it, too.
My understanding is that it was messy. The parents/kid got some money. Maybe $1 - 1.5 million?? But my memory is hazy on that. Obviously, their parents' lawyer took some percentage of that.
I'm pretty sure the (parents') lawyer who hired me took on other plaintiff's lawyers as "investors" (I forget the proper term for what he did). Basically, he didn't have enough money to pay for everything up front [like expert witnesses], so he sold fractional "ownership" in his future earnings on the case in exchange for funds. This was a part of the business that I did not know existed prior to my testimony.
My suspicion is that he took away very little after the rest of us got paid (family, support staff, "investors", etc.).
My deposition was probably pretty typical, but it was shocking to me.
- The defense lawyers flew out to me and rented a conference room at a local law office.
- At around 9AM, the main defense lawyer sat across a table from me and pulled out stack after stack of documents and I thought, "Wow, she brought a lot of extra reading for herself. I should be done here by around 11 and I can go home and mow the lawn."
- NOPE! Every stack of documents was there to rebut some specific sentence that I wrote in my initial report.
- There were a lot of insults and efforts to get under my skin. For example, after I used some technical term, she said, "That's a big word. Do you really know what it means?"
- The only reason the deposition stopped was because she had to catch a flight back to the west coast around 5 PM.
- The kicker was that "MY" lawyer asked if I'd be willing to give them BOTH (plaintiff AND defense) a ride to the airport (defense lawyer said she'd pay me my rate for the ride).
- I told them I had to get home, but really I took the whole thing too personally because I thought, "You just insulted me for six-and-a-half hours? Now you want me to drive you to the airport? I'll pass."
- And then the lawyers took a taxi together like they were old friends.
Obviously, it's just business for them, but I'm not built for that.
I was a small-time expert witness (on the plaintiff's side) against them in a very small lawsuit. It was the first and last time I served in that capacity.
A child was born with horrific birth defects. Parents claimed that a specific medication caused it. Pfizer obviously said otherwise.
The whole thing left me feeling dirty. Experts charging $600 / hour (this was over a decade ago, so God knows what they charge now) to say, with diamond-hard confidence, whatever their side wanted them to say.
Plaintiff's experts: "That drug _definitely_ caused the birth defects."
Defense experts: "There is no possible way that drug could cause birth defects."
Basically, here was a tragedy, and we all feasted on it. One of the other experts told me I could be "good at this" (selling myself out as an expert), but it just left me feeling dirty.