If you click the link and click on the 'video' tab you will see the news segment that ran on TV about the dryer installer's death. In the segment, there is an electrician testing the medicine cabinet and getting a reading of 120V. The little dry wall screw that barely pierced the romex created quite a hazard. I would think, code requirement or not, it would be a 'best practice' in the trade to bond a metal stud wall with electric wires running through it.
