A NDA is a much different beast than a non-compete clause. I have signed NDAs to work on school projects before, but that did not really affect anything I did outside of the class project. I don't think an NDA would close off any job opportunities. The subject of the article signed a non-compete clause, which prevented him from getting a good job opportunity. I don't think those have much in common.
You're right in general, but not in this specific case. The NDA was so strong that if read as written it basically forbade us from ever using anything we learned with them, for any purpose, ever. It did not narrow itself down to internal operations.... which we would not have been privy to anyhow! We weren't going to be sitting in on trials or hearing about their cases anyways. It was almost stronger than what you would consider a "noncompete" in that sense.
And since it was a lawyer's office we were little inclined to assume they'd never exercise their claimed powers.
And again, we were paying for this course, not being paid. (In fact their "due consideration" clause alone was a bit amusingly handwavy. It was nearly "for the due consideration of being graciously allowed into their presence to bask in the glow of their wisdom.")
