I heard a better story from a retired GE engineer who worked for the DOD at the time. He claimed (with a serious and straight face) that Fidel had indeed given the command to launch. The Russian missile installation was built mostly with Cuban slave labor, and Russian supervisors. The translations and drawings were poor on the best day.
The poor Cubans that turned the first launch keys were instantly electrocuted, and the command center totally fried, as the Russian to Cuban Spanish for "twenty and one hundred volts, to ground" came out "twenty-one-hundred volts, grounded".