The prosecutors always call the "expert witnesses" most willing to purjure themselves in front of a jury that they can get "on their team". They're also prohibitively expensive for the defense most of the time, and have a previous or ongoing relationship with prosecutors. Unless the defense are experts themselves it's nearly impossible to reframe or correct the information to the jury, their mind is typically already made on whatever has been presented at that point. Under oath they're supposed to present facts as a neutral party, but this is almost never the case. I think "expert witnesses" should be picked the same as jury selection by both parties, or at least agreed upon from a pool of individuals. Talent is hard to find though, especially cheap talent. So no, I don't really think any "expert" testimony with the way the justice system works today is fair. This isn't a new issue by any means: https://en.m.wikipedia.org/wiki/Steven_Hayne