Other commenter is a bit harsh; this event was to teach Seungwoo about the cruel and unpredictable nature of the survivors. He isn't #1 in the world, or top ten, or even top 50. He's just above average with a good talent. How is he supposed to know this guy has a monster-transformation serum when he doesn't even know they exist? None of the items he's seen thus far have actually resembled anything created on earth, so a modern-looking injector would probably just be a painkiller or something.