Spent some time in a sadly futile exercise of trying various relatively non-invasive things to find why the 320d won't start. Could be timing I suppose, although seems unlikely given it was running perfectly before stalling when I lifted off the throttle while travelling at ~85km/h.
The obvious thing is to read codes, but that can take some time when it's impossible to get the car to the diagnostic kit. Fortunately, a Very Nice Man has offered to loan me something that should help.