I appear to be stuck on a lift.
After re-establishing landline communications, I got back into the lift to return back inside the facility, and after the lift came to a stop and the doors open I found myself unable to move. The game is still responding because I'm still getting Mira's voice overs telling me the power is down but the game is otherwise not accepting any movement. I am also still able to look around.
It is not possible to save the game (the save option is greyed out), which would have presumably allow me to reload the game again and resolve the problem. My last auto-save is a couple of missions back (about an hour ago) so I'd rather avoid loading that back up if I can avoid it.