> That doesn’t seem to account for some of the weird patterns we see, however.
The author is overthinking it. The most likely scenario is that an official email went out to all webmasters with the message "Shut it down NOW, people. And then go home." The assorted webmasters then executed the shutdown with varying degrees of skill and diligence before heading off for a drink. Thus, some subdomains are still available, redirects are implemented inconsistently, etc.
Here's a list of agencies[1] exempt from the Antideficiency Act[2], a more interesting question would be: are any of those websites down?
[1] http://www.fas.org/sgp/crs/misc/RL34680.pdf (p13)
[2] http://www.gao.gov/legal/lawresources/antideficiencybackgrou...