Hi
@Susan
Oh Dear...I'm so sorry you went through a terrible ordeal but more importantly Thank God you were unharmed & safe.
I have a theory about how your watch was magnetized but looking at it from a different angle. Other readers may offer different explanations
In a flight or fight response to a perceived harmful threat, the body produces Adrenaline & Noradreline . Many biochemical cascadings reactions occur & one such response is excessive perspiration / sweating/ diaphoresis.
Quite possibly you have an unusual high number of sweat glands located around the wrist forearm & back of your hand.
One such important negative electrolyte present in sweat is Lactate or lactic acid. When electrons are removed from lactate by certain enzymes , they flow from a negative to a positive terminal generating a weak electrical current in the opposite direction & creating a small magnetic field around your wrist. The idea may seem somewhat absurd but not impossible.
For all i know you may have an inborn gift of creating transient strong levels of magnetic fields around you in times of stress. Try wearing another watch & see whether you reduplicate the process in a safer controlled environment like some strenous physical sports activity.
Heck ! It's worth a shot , Mrs Magneto !