I should add that I referenced the 1991 edition of NDS.

I cannot strictly account for difference between the material lab tests to failure and approved design values but consider this: the lab test evaluates what the sample can withstand right now under a set of specific conditions and design values give authoritative assurance on performance without degrade over decades under much wider conditions. In a way the tests tell us that wood is strong and design values tell us that time is the leveler.