Pretty poor etiquette all round really. Porsche driver obviously either a complete d*ck or just not very good (or doesn’t know the track), but why the Bmw and Nismo then proceed to follow him so closely I don’t know.
The whole video is just begging for an accident. If someone is being that rude to not let you by, then why waste your entire lap sat behind him: Ease off, find some space, then crack on.
But yeah, when on track ffs use your bloody mirrors!