I agree exactly-- you expressed it more eloquently than I, but I too found the shop owner arrogant and possessing of a missive ego.<quoted text>
I found the shop-owner to be the sneaky and disrespectful one. He was the one that sent a customer on a long journey only to bring him back to the very same store. The shop owner was the one that seems to think he knows better than the customer what is good for the customer. And that is arrogance. The shop clearly didn't have what the customer wanted, yet the shop owner, promising a better shop, wastes the time of the customer and then gives exactly what was already determined to be insufficient.
Perhaps the shop owner saw the customer as being smug and cocky when he simply knew what he wanted and found the shop didn't have it. It seems to me that it was the shop owner that sought to belittle the customer, not the other way around.
Your lesson is mixed up.
In his massive pride, he could not let a minor insult go unanswered.
Rather like the bible's god, come to think of it...
... no **wonder** he got the lesson wrong!