Hughes500 - A low battery voltage or "brown out" (Low voltage dip) as you change over from cart to battery can cause the FADECs to fault and the EBACU will step in and command the NR to flight. As you found out it will ignore the throttle position! This should not happen since the FADECs have their own generators attached to the NG shaft but weird stuff does occur.
Watched a B3 start by itself about 30 seconds after it had been turned off by the pilot. The look of confusion on his face was priceless. He had not placed the START switch into the OFF position properly and it skipped back over the gate into the FLIGHT Position. Once the NG had dropped below 10%, The FADEC saw a valid oil pressure signal so decided it needed to do an inflight restart.
And on bad grounds. I had an AS350BA that developed corrosion on the ground plane on the UHF antenna and it was affecting the bleed valve!. When it was raining and you transmitted on the hospital channel, The bleed valve would close. It made no real difference in flight but was not kind to the turbine when at ground idle. Explaining it to Engineering got me some weird looks.