With two expert witness jobs on the books, (both awaiting court dates), and a part 35 report about to be sent out, there looks to be a lot of this work. It is well-paid, but I'd rather maintain my engineering practice. I enjoy it, and it keeps me current and credible.
There are too many "experts" who have never designed or operated a plant, and are not even qualified as engineers, who nevertheless seem to manage to persuade courts as to their credibility in offering an opinion on engineering matters.
Then there are those who used to be some kind of engineers, but who now only seem to work as expert witnesses. They claim expertise in a very wide field, sometimes far from their original experience and training. They seem to be experts in being an expert witness.
This is why it is so important for me to continue in professional engineering practice, and to only work as an expert in areas close to my maximum experience and expertise.
I'm sure than many who write reports on subjects far from their real area of expertise must be terrified than one day they will have to stand up in court and defend their opinions. Personally I look forward to it.