ZP: Is the path in the darkness a bug or ...? (STALKER: Call of Pripyat)

With a partner I left the dungeon, going from Cardona to Agroprom. In the subway, they were banging on something. The partner stays with the debt workers, I myself run over the hillock to some hermit for an antidote. I go back, I go to my partner. He lies karyachitsya, does not take the medicine, in the sight it burns red, like the enemy, time is running out and both, both dead, the end of the game. What's wrong? Explain