I'm not familiar with the crash recovery procedure, are the marshals supposed to press the discharge button when recovering a car?
to answer your question:
In case of an "normal' accident/incident
30.5 A driver who abandons a car must leave it in neutral or with the clutch disengaged, with the KERS shut down and with the steering wheel in place.
The question is what happens in a "big" accident, ala Kubica in Canada or similar, with the driver incapable to operate the systems after a big crash.
As with refueling, KERS has the "potential" for a incident, it's just a question of time, when it will happen.
But let's not jump to conclusions, it remains to be seen, what has caused the garage fire at Williams.
Sad end, to an otherwise great day for them.