ANSWER: while drinking with a regional security officer, he explained that the evac had nothing (directly) to do with the political unrest. Turns out, during the height of protests, Mubarak released a crap load of criminals from the prisons and told the protestors to choose between holding their ground in Tahrir square and protecting their own homes. So everyone went home and the boabs set up armed checkpoints at every block and wouldn't allow anyone they didn't recognize access. So, the expats were completely immobilized and couldn't get basic needs.
Not that great of a story, but it was new to me and I wondered if it was something other people knew.
