Autopsy is too vague

I spent all weekend beating myself up. As a mother I really did fail at the one thing a mother is supposed to do: keep her child alive. After a month of thinking this over I believe it was a trait that I used to count as a positive one that failed him.
 After reading his autopsy report I am sure he killed himself Tuesday night. So first I felt horrible for not finding his body sooner. It was cold. I only went outside once on Wednesday. It is hard for me to believe that I did not see him then. Several people came and went that day. It is unreal that nobody did see him. He was hanging in a small building with a both a window frame and a door frame that are wide. I had not gotten around to putting in a window or door yet. He was visible from the street. Nobody who was here can believe that he was there on Wednesday. Diva cried when I told her I thought he was. She is sure she would have seen him.
The day he died Fria Chica told me that she had talked to him Wednesday morning. She pulled up early in the morning. It was still dark outside. My mom's headlights were shining a small amount of light into the building. She said that he was looking down at his phone and would not talk to her. That did not alarm her. Often if he was in a paranoid mood he ignored people, or talked so quite he was hard to hear. She was in a hurry so she took this as assent that she could borrow his car and rushed off to work. Since driving caused him to have a harder time controlling his thoughts he did not use his car much and she had been driving it to work everyday.
I did not know Fria Chica had taken his car, so I thought that Jason had taken his car in the middle of the night. My mom said that Fria Chica told her Jason was in the building as she left. My mom climbed the steps to the building and stood in the doorway. She did not go inside. She looked around and did not see him.
All of this led to much confusion and conversation. Was he in the room alive when Fria Chica talked to him? Did he hide from my mom? Could he have survived all night out in the sub-freezing temperatures in his thin jacket? I kept thinking it was a different scenario.
I suspected he had killed himself Tuesday night. Fria Chica does not have the best eyes. She is also not observant when she is in a hurry. Jason did not have his phone. He left it on the kitchen table. I think he was looking down because he was hanging there already dead. Something deep inside of Fria Chica knew this too. She was over emotional all day. At the end of her work day she walked off and quit without a word.
What then of my mom? She has poor night vision like Fria Chica. She also has a strong defense mechanism that leads her to forget things she does not want to remember. Whenever she talks about the past I wonder if we lived in the same universe. Could her mind just have blocked him out?
I have suggested that maybe there was some sort of spiritual veil over him. How else could so many people have walked passed him and not noticed him. I think I was supposed to find him when I did.
Most everybody else believes he could not have been there all day Wednesday. It must have been after dark on Wednesday when he died.
We have been waiting for the autopsy to see when the doctors would place his time of death. They left it as undetermined. The blood analysis from the state is not back yet. If he had meth in his system we would know that he did leave Tuesday night. After looking up a few things in the report I really believe he did kill himself Tuesday, right after I talked to him. The report had said rigor mortis had passed. Of course freezing temperatures make rigor mortis less accurate as measure for time of death.
His body was frozen when found. The autopsy said there were signs of post mortem hypothermia. He was missing for about 36 hours. I do not think rigor mortis could have set in and passed in much less time than that.