The ultimate reason why this person developed slightly antisocial tendencies

Actually, there is a reason why this person developed slightly antisocial tendencies. In truth, this person was an honest, diligent, and kind individual.
He was someone who ranked first overall among the five major public institutions and received perfect scores on interview evaluations three times in a row. That is why even the HR manager within the public institution said, "This person is not problematic; he earned his position through his own merit."
However, the human rights violations by the police officer were too severe. It was at a level that could be described as the annihilation of human rights. For example, while exercising, he heard things like, "Hey, you mental patient bastard. I slept with your mother." In other words, the police officer resorted to verbal abuse because things were not going his way.
But this person had never heard such things in his entire life. That is why he felt so miserable. His mental condition worsened after hearing such words.
Despite this, he was still grateful to the women from Busan he met, and he felt deeply thankful for the company he worked for.
But because he started shouting in public, people at the public institution wondered why he was acting this way, saying it wasn't the person they saw at the company.
In other words, a person who knew how to be grateful and had served as a class president and student council president felt miserable because he heard things from a police officer that he had never even heard at home.
Consequently, the individual developed dissatisfaction and hostility toward society, which led to these slightly antisocial tendencies.
The truth is, the police officer's violation of human rights was too extreme.
He heard things in his life that he had never heard before.
Because of this, even the women from Busan he had been grateful to became targets of his retaliation. These women, knowing nothing, said, "Let's kill him."
He is not that kind of person. Due to the extreme human rights violations, feelings of anger even extended toward the company he was once grateful for.
In fact, the reason his trust in the company was broken was that while he was trying to endure the hardship as told by the police, they told him to endure it based on this company he was so grateful for, which caused his trust to fail. In other words, they used the company to gaslight him.
Ultimately, it was your investigative methods that caused the problem.