Impolite Shoe Shiner
Every major city in the world has its share of scammers trying to target tourists. People visiting Istanbul, for example, are told to avoid shoe shiners. The OP shared his first-hand experience when he was just walking around and a shoe shiner in Istanbul “accidentally” dropped something.
After he pointed it out to him as any decent human would do, the shoe shiner thanked him profusely and proceeded to shine his shoes making him think it was a favor. Once he was done though, he suddenly got aggressive and started asking to be paid for his service that the OP never asked for in the first place. That’s just crazy.