Not about tasers, but related to original question:
Lightning Specifics
Voltage in a cloud-to-ground strike is 100 million to 1 billion volts.
20% of all lightning victims die from the strike.
70% of survivors will suffer serious long-term effects
From
Lightning Facts 100 million to 1 billion volts only kills 20% of people it hits.
It's the amperage that kills.