Oof, I always wondered if there were more things of his that were inaccurate.

What I caught was the hexagon video and his claim about triangles (combined to make hexagon) being the best for building rockets. I worked in the launch side of aerospace at the time, and true Atlas V and Delta IV were built with triangles.... But only on their booster tanks. Their upper stages had a completely different design structure, as do Vulcan, Falcon 9, Starship, New Glenn, Electron, etc etc

Triangles were only used on Atlas V and Delta IV because CAD in the 90s didn't do rectangles very well. That's not a problem anymore, so triangles don't get used