He was a DA. If the show was wrong, he would SUE them, not off himself. He gave them his phone number and email address. It could have been planted but a DA would know how to defend himself better than anyone. It is possible to lie about phone numbers and such but very hard to line up all the computer network stars. They had this guy dead to rights and he knew it.
If the police and an NBC crew walked up to my house, I would go look at new cars because I am going to get paid.
They had a warrant. That means they had probable cause, and a judge and prosecutor agreed. Unfortunately his suicide leads to two possible conclusions, either he was innocent and so ashamed that he was falsely accused that he killed himself, or he was guilty and rather than face the consequences, he killed himself.
It is always tragic when someone dies, and in this case, seeing as how the some of the other cases did not stand up in court, there may have been a way for him to walk away.