This interaction seems to suggest that eating/drinking something in Kowloon has bad implications for those that do. Maybe you'll be put under some spell or be unable to leave Kowloon. It reminds me of the Greek myth of Persephone where she is obliged to visit the underworld every year after consuming some pomegranate seeds:Hebinuma: Don't tell me you...?
Gwen: Relax, I didn't eat or drink anything.
Before leaving the underworld, Persephone had been persuaded to eat four seeds of a pomegranate. In ancient mythology, to eat the fruit of one’s captor meant that one would have to return to that captor or country, so Persephone was doomed to return to the underworld for four months of the year.