I have no doubt that they are great at their job, but when it comes to lawsuits the judge(s) are equally as important. You could get everything right but a judge has extreme power to interpret the law or even ignore it in select cases.
I wouldn't say they ignore the law, but legislation like FOIA has a lot of discretion to balance competing interests and that's where a judge would make the most different despite all the great articulations of the most brilliant lawyers.
There are very few public bodies that do a solid, to-the-letter job of complying with their open records requirements. Almost all FOIA failings are due to the fact that it isn't staffed adequately; FOIA officers, clerks, and records attorneys are all overworked. When you do a bunch of FOIA stuff, you get a feel for what's going on with the other side, and you build a lot of empathy (which is helpful in getting your data over the long run).
And then other times you run into bloody-mindedness, or worse.
I don't think NIST has many excuses here. It looks like they botched this straightforwardly.
It's a straightforward case. My bet is that they'll lose it. The documents will get delivered. That'll be the end of it.