Guo's appeals were all dismissed until 2013, when the Guangdong Provincial High People's Court accepted the case. Last month, it overturned the conviction on grounds of insufficient evidence－nearly three years after Guo was released from prison.
"I used to have lawyers, but they thought I had acted excessively. We had different ideas, so I defended myself in the appeal hearing," he said, adding that he saw his daughter for the first time since his conviction last summer.
Hearing the news of the appeal, Jiang Yalin, a mother in Jiangsu province whose daughter was also poisoned by tainted milk powder, gave a thumbs-up.
"I tried to get some funds for the affected children, too, but I failed," she said. "I gave up, but he didn't."
The experience has come at a price for Guo, however. The lengthy time in prison has affected his health, he said, and his wife also divorced him shortly after his conviction.
"For my family, a confession would have meant I could get out earlier, but for me it was like admitting I'd made a mistake," he said. "I had no choice: If I wanted to safeguard my daughter's legal rights, I had to sacrifice the time I would have with her."
Guo, who is currently unemployed and lives on a 1,000 yuan monthly welfare subsidy from the Beijing city government, said he plans to return to Guangdong to meet with Yashili to discuss the 3 million yuan compensation.
"I'll go and ask for an answer, no matter who is in charge now. They should honor their commitment," he said at the teahouse. "I can only focus on one thing. All I can do now is end this case as quickly as possible."
Guo said he also plans to apply for State compensation for his wrongful conviction.
A spokesman for Yashili, who did not want to be named, said last week that the company would respect the verdict, although he did not know about the compensation claim.
If Guo appeals to a court and the court acknowledges his evidence, the company will abide by the court rulings, the spokesman said.