Song Qingxiao was deep in thought. She wondered why the doctor had not killed number two—the office lady. Number seven's death cleared up the issue for her.
When the game officially started, Song Qingxiao had pinned the doctor and the burly chap as the most difficult people to beat. Similarly, the doctor had made a similar deduction about the trial situation. Number seven's muscular physique made him everyone's biggest foe.
If it were a game based on logic, the doctor would definitely not lose. However, in that game, the trial was not merely a test of intelligence but also physical strength and combat skills. If the doctor killed number two, he might not be able to win if he encountered number seven.