Cordless drill used for brain surgery

As reported by the ABC and other media, Dr Rob Carson used a DeWalt cordless drill to a hole in the skull of a 12-year-old boy top relieve bleeding to the brain in Maryborough, Victoria.While obviously an emergency measure, cordless tools would seem to be a good choice for this as they would reduce the risk of electrocution. From the photos shown in the media, the unit used appears to be a DEWALT DC759KA 18-Volt Ni-Cad 1/2-Inch Cordless Drill.