AFAIK, the same is true of the USA: its international airports are extra-territorial possessions in which the USA is not obligated to enforce its human rights agreements ...
The exception is that the airport is not a part of the UK sovereign territory, but is rather considered an extra-territorial possession of the UK, akin to a colony, which can be governed separately.
It is a wholesale violator of human rights at massive scale and therefore the precedent for protection of rights under that state is simply non-existent. Magna Carta, Habeus Corpus - irrelevant given the massive, immense scale of the UK's wholesale abrogation of billions of human beings' rights.
>That you want to swiftly send him to jail tells me totalitarianism is becoming fashionable again.
Every single human being alive has the capacity to manifest the totalitarian-authoritarian personality. We are not immune to it as individuals - our only safety from this viral meme is social. It is only when we have a social order that provides more motivation to eschew the totalitarian-authoritarian personality, at an individual level, that we are actually free of it. The irony is, this personality also arises when an individuals' own personality is challenged by society.