Chi, I hadn't read the others' responses before I posted. They made excellent points.
The very fact that this man is phoning you is a huge red flag.
I agree with @Ed-and-Hugh0. Report him to the police.
I've had a look at your listings. I'd suggest that you set up more stringent guidelines in the House Rules section, including that guests are required to have health and travel insurance.
I understand you might not want to list a lot of 'do's' and 'don'ts, but after reading hundreds of posts on this forum over the past couple of months, I've completely changed my approach from 'warm and fuzzy' to 'objective and clear'. 🙂
It's important that guests know exactly what's required, and - one hopes - prevents misunderstandings. This helps ensure that the right kinds of guests are attracted.
Of course, I realise that your current situation is quite out of the ordinary.
I'm sure you have an email address for the guest himself. I'd suggest emailing him to say that any complaint must be registered with AirBnB, as the matter is out of your hands. If the father harasses you with one more phone call, inform the police.
Maybe you could even record that phone call.
In any case, have no further contact with either the son or the father.