Understanding Epictetus' burning down of the Capitol

Excerpt from Epictetus’ Discourses, Book I, Chapter 8 (emphasis mine):

You know, I once said the same thing to Musonius when he reproached me for not discovering the omission in a certain syllogism. I said, ‘It’s not like I burned down the Capitol.’ And he said, ‘Idiot, the omission here is the Capitol.’

I mean, are these the only crimes, killing your father and burning down the Capitol? But to use one’s impressions recklessly, carelessly and at random, to fail to analyse an argument as either valid proof or fallacy, and, in a word, to fail to see in the act of question and answer what agrees with your position and what conflicts – is nothing wrong in all of that?

I suppose that Capitol is the name of some ancient city, but I nonetheless struggle to understand Epictetus’ message here.

Is it:

1. A simile? Not observing that a premise is missing from a syllogism is as grave as burning down a city?
2. A literal correlation? That omission from the syllogism was about the Capitol?
3. If something else, what?

Update: as per @Cascabel’s comment, Capitol is a building part of the The Capitoline Hill in Ancient Rome.