The Rabbis were actually quite aware that a solar year is actually slightly more than 365 1/4 days.  They were living in Bavel which had the best astronomers in the world at the time.  They just assumed that the messiah would come before it caused too much inaccuracy.  However, you are right that they weren't that great at math, since they assumed Pi to be exactly 3.

"FSM is useful for mocking religion in a certain way."

Really is it a mockery of religion or a mockery of the way religion is abused so that it will be given a free pass when it comes to the epistemological quest?  Bobby Henderson's site is really quite respectful of the religious experience, but rejects the notion that the religious experience can be known to be objectively true.  One person, or a large group of people, may believe with utter sincerity that there is an imperceivable metaphysical aspect of the universe.  Whether or not that aspect is objectively true, something that religious believers can not prove (nor should they wish to prove) by its nature has no place being promoted in a setting where  objective, verifiable truth is claimed to be taught.  What can be learned from a religious education can also be learned from a solid secular education that includes the study of religious expression as found in the form of religious texts such as the Bible and iconography without promoting personal belief as well.  One doesn't need to believe in the tenants of a religion to appreciate the power and influence that the religion has had upon the other aspects of human culture.

Well, it is Chicago, where it is considered perfectly kosher to be corrupt.

But seriously, I think that both the mashgiach and the bread company are at fault.  The mashgiach should be reported to his organization for extorting the bread company and the bread company should apologize for betraying their customers' trust by continuing to sell their products with a questionable hechsher. I think that you should write to the Chicago Jewish News.

I also wonder if this happens more often than we hear about. 

Are the forms that Mailer considers ugly or misshapen really mistakes or actually really well suited for their environments?  Only a life form that comes into being not suited for its environment could be called a mistake, but it wouldn't live long enough to perpetuate itself.  So it must be that there aren't really any mistakes.