> Artemis acceptable crew mortality rate is 1 in 30.

So with 4 crew members, chance of one dying was 13%! Very lucky they all survived.

That is not how statistical calculations of risk are made. If the crew has 1/30 crew mortality rate, and there were 30 crew members, that does not mean there is a 100% chance that one dies. While there is negligible chances that only a portion of the crew were to return, the outcomes are closer to black and white of nearly 29/30 full crew return and 1/30 no crew return.