Was this shop owner rude or my fault?

I was shopping kpop stuff( idol cars, rulers...) at a box rental shop for my friends as presents, I went in trying to take a photo to show my friends and he says I can't take photos, so I try to write down what is in there and he suddenly say : aren't you very obvious try to copy my idea? Like what is wrong with him, I pick something cheap and buy it to show I am just customer, and I explain what I was doing, I asked him why he thinks people are copying him? He says bc ppl are dumb and not original, I explain to him again and apologized and he is like ugh and look away, like what the hack, I am just an innocent customer and I even apologize, what is his problem? Buy a personality, it is the worse thing I have seen so far and I was questioning myself did I do wrong , like got my day ruined for no reason, is he a jerk? What should I do if I encounter this type of human again?