He claims that the product has a problem. In order to help him better, we hope he can provide further information so that we can analyze the cause of the problem.
We just calmly tell him what information we need, I hope he can provide

And his reply shocked us. He said: Why do you threaten customers like this?

We are confused, we have never used an inappropriate attitude, we just hope that he can provide the information we need. How did this become a threat to him?

His understanding of the term "threat" is really shocking.

This buyer is either having a Paranoid delusion，or just a Fraud been piss off Because he didn’t easily scam successfully.