Well, Alex Garland,screenwriter and director of this film, seems to have travelled extensively throughout Europe, and he does not seem to hail from a benighted petty bourgeois family, to say the least. He might have picked up a couple of words in German here and there. Meeting people naiive speakrrs of German as a young person, it does not seem to odd Alex Garland might have beeb enlightened about the meaning German word "kotzen", and this notion seems to fit with the trauma that the protagonist has to endure, but I can see how some Germans consider that inconceivable.
On the other hand, even Saxonians picked up a little English quite fast after the Fall of the Wall. Which turned out when they were heard on Christmas markets offering their Christmas trees with the perfectly English idiom: "Please pay a Tännschen!"
Alex Garland has actually been quite successful, and I guess many Leonides will know some of his work, especially his novel "The Beach" as I only realised after starting the thread.
#23 thanks, Raudona, for this interesting piece of information.