If you're suggesting that there was not quite a bit of science and math that went into building the egyptian pyramids, I think you're well off base.
I think that's more the point of the blog post.
No, of course not. They're simply highly trusted, generally educated people, who we trust to make roughly okay judgment calls based on their instinct and life experience.
Ethics isn't a field you can study the same way as biology or anatomy. It's about compromises, staying within the broadly socially-culturally acceptible. Sure the moral intuitions of a society do evolve over time and often due to influential philosophers, but I don't think everyday ethics committees tap into anything deep.
It often comes down to an extremely uncertain medical situation where the doctor can provide no useful quantitative probabilities for outcomes and the benefits and risks are really hard to score anyway. So it all comes down to intuition and negotiation and not upsetting the public too much.