“Different parts of London have different accents.”
True. But, Received Pronunciation is common in North West London, where the bulk of non-chassidish frum Jews live, and where I spent 7 of the last 10 years.
Herr Rabbiner is German. If you know Dayan Krausz Shlita, it would make perfect sense. He is originally Swiss, but is very ‘Yekkisch’.