Exception?

Stacked Canoes near Little Miami River, Harrison, Ohio  © Doug Hickok
(Click on image for larger view.)


This black canoe is the only one in a stack of red ones. It is the oddity, the rara avis... which begs the question... does the exception prove or disprove the rule? This is a question that dates back to the Roman orator Cicero, from a rhetorical defense of his client. For example, would it be truthful to say that all of Doug's posts this week have the color red, therefore, red is always in his posts? Or, is it ordinary for Doug's posts not to have red, and this week is the exception that proves it.

More likely this is all just idiomatic gobbledegook.