John,

  What is a "weak" ground?

  Any high-resisitance connection (including too small a cross-section for the current being passed) will encourage current to flow through another, lower resistance, path.    Gotta wonder why that particular spot got hot, though.
Seems like the heat would be distributed along the entire braid.

Dale R.
[notice you got more responses here than on the CAF?  ;) ]