a "spark" of truth
Cellphone batteries do regularly explode or catch fire. There is a LOT of energy stored in that little can of lithium. Without very careful charge and discharge monitoring they become quite dangerous. If you're interested the radio control forums on the internet have lots of articles on their rather high powered ones going up in smoke during charging. A LiIon battery requires a protection circuit to monitor current flow and temperature and to shut the battery down if either one is out of scope. If you short a lithium battery it must shut down because otherwise it will explode. The protection circuit normally handles this OK, but not always. And some counterfeit brands dont bother with that little feature at all... Then ask Sony how much it hurts that their defective cells caused thousands of recalled batteries form dell and apple and lenovo and I dont know how many more because even with the protection circuitry they still caught fire...
But the rest of the story is completely bogus. Nobody has gotten electrocuted from a 5v battery charger.. I suppose it's possible that the power supply failed in a way that just send line voltage through to the phone... but I would not expect the phone to actually be working in a way that it could accept a call after that happened...
