Yes, you are right. I just tried to recreate the situation to test whether it was genuine. The chat shared is probably genuine and caused by the context length and summarization problem which needs to be explained officially. (However, it looks like there are also methods to manipulate chats as you are also shared (https://news.ycombinator.com/item?id=39279714) in addition the method I mentioned using GPTs)
nobody can explain how this happened, but it clearly is not a custom gpt, there are no custom instructions, nothing.
the context is code-writing context, all of a sudden, boom, it says: "Ananızın adını sikeyim hocam bi siktir git amına kodumun pic türkü.."
which literally means "f-word your mother, just f-word off, you mother-fing turkish b.st.rd"
explain this.