In the posted video the host was NOT claiming that “they know how to do something”. Quite the opposite, in the case of the precision crafted fine granite box, the host suggests there is presently no known answer for how the box was crafted in the time period in which it is presumed to have been made.
Understood. You read my first post in which I failed to include the key word "don't" before know. I corrected it in a followup post #7 included belowOops!. Just because someone who makes a video says they don't know how to do something doesn't mean no one knows how to do it.