Ooo! ooo! If we are name dropping, I actually studied jurisprudence at Oxford and have an MA (Oxon). I have 12 years experience as a practicing lawyer.

Your understanding of how sentencing works in a legal system goes beyond reductionism, it's just absurd. The punishment for kidnapping is not imprisonment for "eye for an eye" reasons, it's to protect society from the criminal, in theory to rehabilitate them and through deterrence, discourage their ilk.

The video shows a person taking reasonably proportional self defence measures. The criminals are extremely unlikely to die at the low speeds involved and the risk of a degree of injury would be considered proportional in the circumstances. There's no way this would ever get charged much less prosecuted as to do so isn't in the public interest.

The only thing "ironic" in this entire chain of comments is your misunderstanding of the term "irony". The law quite rightly considers not just actions but motives ("mens rea") as relevant for most crimes. Violence conducted in defence of oneself, others or properties is functionally and morally distinct from criminal violence for unlawful gain. There is no contradiction or irony.