I tend to trust the forensic pathologist. Surprised so many people are questioning it. I think that we simply don't have the information like they do. We don't know the depth of the rake holes or the angle. It may well be that when you place the rake on the floor on the flat it is impossible to fall onto it to create the angle of holes that were in place.
To me it read like she was bending down (possibly to pick up a pet carrier) or walking away and then events happened.
The automatic assumption that a teenager could not do this really concerns me. Of course it's likely that he didn't, but why didn't they actually investigate it to rule him out, especially given that Amy was placed on top of the son in the truck? I just say this because we have seen time and time again that things can be surprising. If someone is physically capable of something then they should be investigated, not ruled out based on assumptions. Then everyone can feel more confident in the verdict as well. It concerns me that they don't investigate and just automatically rule it out? Likewise with the fingernail clippings which after a homicide just seems not right.