Has anyone experienced full car shutdown during an extreme vehicle maneuver?

A co-worker of mine with a '04 Package 7 was cut-off in traffic by a dump truck while traveling ~50MPH. After standing on the brakes with both feet she got to experience what her dealer called an "Emergency Battery Cutoff". The explanation was that the Prius uses the airbag pre-crash inertial sensors (the ones that determine whether you get a 1 stage or 2 stage airbag deployment upon impact) to disconnect the HV battery pack and accessory battery in anticipation of a crash. This caused the ICE to stop and all power to the vehicle to be cut (other than possibly headlights/taillights). She pulled to the side of the road with an apparently completely dead Prius. After 30-45 seconds the Prius came back to life as if nothing had happened.

Anyone else experience this shutdown or have a more detailed explanation of the mechanics of the safety system?

2004 Toyota Prius
Package #9, Millenium Silver
"Boo"

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