According to the doctor's conscience. Dr Yu has been helping criminal groups to develop rhubarb capsules. He has been taking money from criminal groups, so he has done many bad things for money. Dr. Yu had no medical ethics and made rhubarb capsules with what he learned, which killed many addicts. Dr. Yu doesn't feel sorry for the addicts at all, because he feels that the addicts are willing to embark on this road themselves. Wan is different from those addicts. When the doctor saw that Wan was going to die with those addicts, he still felt guilty. He didn't want to see a lovely girl leave like this, so he rushed into Wan's home.
Dr. Yu doesn't want any trouble. Although Dr. Yu participated in the criminal activities of criminal gangs and developed rhubarb capsules for criminal gangs, he always participated in the activities behind his back. He doesn't want to expose himself in front of people, but even if a criminal gang is exposed, he will be exposed sooner or later. Hao Dong escaped, and he will face such a situation sooner or later, so the doctor doesn't want to get himself into too much trouble at this time. He knew that Dong Ge had escaped, so he would rather end the matter, and he also wanted to send Wan directly to the hospital.
Doctors are greedy for money. He develops drugs for criminal gangs. They will give doctors a lot of money, but doctors will not be well paid and will not do business at a loss. Now that Dong Ge has escaped, he doesn't want to kill Wan without money. Hao Dong won't have a happy ending, so Dr. Yu certainly won't kill Wan for him. It is precisely because of the doctor's move that the nurse became suspicious and the police became suspicious. How did he know what medicine to give Wan? Which means he had a plan a long time ago.