No idea what may have led to the guy losing his mind and pulling the knife. The driver was incredibly lucky that the car with the dash camera had backed away enough for him to make an escape after the “misguided” member of society breached the window on the passenger side. According to the article in the Daily Mail, the owner was unharmed and recovered his vehicle once the aggressor left the area.
I am sure the perpetrator, after consideration and deep soul search, decided to turn in his knife to the nearest knife amnesty bins located across the Once-Great Britain.
Hat Tip Brad W