How does Rachel's opinion tell anyone that it wasn't an accident? That just tells you - Rachel's opinion. It doesn't tell you anything at all about what actually happened. Just a guess but that is how I interpreted big_pimpin's statement.
This was the direct quote from Rachel. "this day will not bring closure only until the person responsible is brought to justice"
If she thinks someone responsible needs to be brought to justice, that in my opinion, does not imply Rachel thinks her mother's death was an accident.
She also stated the following. On her father Wayne Pope, I asked if she stood by him: "Um yes. Well yea. I just really don't want to answer that question now."
In my opinion, Rachel not wanting to answer the question as to weather or not she stands by her father is also quite telling, but again this is just my opinion.
Even though Rachel's opinion does not tell us what happened, obviously because nobody knows what happened unless they were there when the incident occurred, it does tell me that she believes for whatever reason that her mother's death was no accident.
Weather or not Rachel is correct on this, is impossible to determine at this point because we do not have the autopsy results yet. However, being that she is an insider and has direct knowledge of her mother and her father's relationship, behaviors, and probably has knowledge of her father's actions, attitude, and weather or not he was acting unusual after the incident occurred, I believe her opinion is not irrelevant.
At no point in time did I imply that Rachel's opinion tells us what happened. However, what she thinks is not of little or no value especially considering she has direct family knowledge, insight that none of the rest us have. JMO