I do not believe that the relative "safety" of one system over another had much effect on which system was eventually adopted.
Rather, I believe the issue was entirely decided by our ability to transform AC. Imagine how meager our transmission network would be, if the wires had to be 4 ft. diameter, and a tower placed every 100 ft.!
Yet, that is what we would have to deal with if it were not for our ability to raise the voltage, transmit the power, then lower the voltage to reasonable levels. You can't do this with DC.
