You're right, "Lawyer up" is more of something you do once you are arrested, regardless of how ambiguous or pretextual the whole encounter appears.
And Hiibel v. Nevada isn't applicable to every state, only those with Stop & Identify laws. IIRC Hiibel v. Nevada even mentions this in reference to Kolender v. Lawson.
There is quite a bit of difference between complying with legal requests by a law enforcement officer and answering vague open-ended questions that are superfluous to a LEO's execution of their job. Questions like "Do you know why I pulled you over?"
, "Why are you in such a hurry?"
and my all time favorite: "Is there anything illegal in your possession that I should know about?"
But to be fair, you are absolutely right.
When subpoenaed to appear before a grand jury and give testimony there isn't much you can do. And historically federal criminal prosecutors have used subpoena's to force individuals to divulge sensitive information against other members of their family, friends, cliques, groups or organizations. But some subpoena's can be squashed (not saying that is very likely or easy with a federal subpoena...) and most importantly, going in with the mindset and knowledge that you aren't going to some how miraculously say the magic words
that make the situation all better is an important piece of information to understand and remember when answering questions. I'm sure a practiced attorney could help coach an individual on how to answer questions and the exact scope of the required complicity a subpoenaed individual most provide.
I.E. if a criminal investigator is asking you questions, they aren't asking you questions to get information to exonerate your friend/family member/self, that is not their job (that is your friend/family's defense attorney's job). They are asking you questions to give them evidence and help them build a case to so they can bring charges and/or convict someone of a crime.
On a side note, I present this quote from Supreme Court Justice of the United States Stephen Breyer, quoted in the oft famous (and I think cited several times on by other commentators on this topic...) "Don't talk to the Police" youtube video, as quoted from Rubin v. United States (http://www.law.cornell.edu/supct/html/98-93.ZD.html)
“...the complexity of modern federal criminal law, codified in several thousand sections of the United States Code and the virtually infinite variety of factual circumstances that might trigger an investigation into a possible violation of the law, make it difficult for anyone to know, in advance, just when a particular set of statements might later appear (to a prosecutor) to be relevant to some such investigation.”
Again, you are absolutely right. There wasn't much Quinn Norton could do when subpoenaed, but still I think this quote is particularly applicable given the context of the situation that Quinn Norton found herself in her unwitting contribution to the miscarriage and perversion of justice executed against Aaron Swartz.
I think subpoenas and discovery motions are two elements of our legal system that are oft abused to the detriment of this nation as a whole. The former by the zealous over-criminalization of America and the latter by copyright attorneys extorting money from individuals otherwise protected from identification by law. This case is just yet another incident of the rampant abuse of our legal system and what saddens and disgusts me is that there isn't much that can be done about it.