I think it may be a long shot, but this is my take on situation...
Her "lithium battery" was in a pocket "alone"?
I have jeans with metal rivets/punches in the pockets, keeps the denim from ripping as easily as stitches in certain areas. - this is
not uncommon.
another completely odd but still manageable situation... glitter. Back in boyscouts we did lots of "play time" with dangers of household
batteries. A single peice of glitter, perfectly wedged, can cause a huge problem....
I'm just tired of all the lables in the headlines.
It was NOT an ecig/mod that "blew up", it was a simple

li-ion Battery.