Would you hire a doctor by insisting they perform surgery in front of you? Would you hire a lawyer by demanding they filling out legal paperwork in front of you?
If they think of themselves as "tech", you're at the whiteboard, reversing strings in C and playing games with trees. When I interviewed for nearly identical job in a "science" department, someone spent 45 minutes chatting with me about the coding behind projects I had mentioned. I even offered to show or write soome code and got told "Nah, we already looked at your github and it's fine."
Same for lawyers. You'd be targeting someone whom you've dealt or worked with in prior lawsuits (maybe they were the opposition counsel), deals (counsel for the other party), or complex cases involving multiple law firms working for the same side.