Classic bayesian error. The population in question here isn’t the globe, but rather people who have already died from caffeine related causes. Naturally the rate of increased caffeine sensitivity amongst those folks will be different from the population at large.
I never said randomly selection from the global population. The point still holds, even if sampling from only those who have died from caffeine: the LD1 dose, by definition, is still safe for almost all the population. That’s why arguing about LD1 or LD.0001 isn’t particularly useful and comes across as overly pedantic.
Also, FWIW the LD50 can be calculated with censored populations (ie not all subjects have died.) Think about it: if I administer a dose that kills half but leaves the other half living, the LD50 remains unchanged even if I continue increasing the dosage until all have died (or not). LD50 does not require a complete set.