I have often wondered if EA assaulted her but was interrupted by someone else who had a grudge with HF. Perhaps someone associated with RB who is the one that drowned in Lake Lavon in August just before CM went missing. If I recall correctly it was RB and HF who went into the water and only HF came back up. RB was later found IIRC to have drowned. Maybe there were bad feelings from that and someone saw an oppty to hurt HF by hurting CM. Maybe that's what CM was trying to tell HF with all the pics of keys and coming home texts... just a random thought but one that I have often pondered and never posted..
I followed this case closely, and don't recall anything like this. Who is this RB? In any event, your theory doesn't really fit the facts. But EA's trial and conviction did. It told us that up to a certain point, we actually can figure out what happened to CM. Her disappearance was unquestionably tied to what EA did, and we can track her step by step ---
1 being in his company (when he said she wasn't) as they walked into a parking garage,
2 disappearing in a garage (where he was parked next to her, yet said he wasn't),
3 her car never left the garage but his car did and the cams show she never came out of the garage otherwise,
4 the phone ping records showed her body was where he/his car was for the next couple of hours,
5 her blood and DNA found IN HIS TRUNK, and
6 she was never seen again.
EA alone had control of his TRUNK. So up to that point, it was him, and if there was anyone else he certainly knows who. Is it possible that after EA did what he did, some other party came along? Yes, but so extremely unlikely. Why would they have hijacked a dead or dying body of CM? Occam's razor tells us that what happened next after she was bleeding (and/or dead) IN HIS TRUNK wasn't someone else, but by EA, who did something with her body that we have been unable to figure out (and might never), because the geography is so massive in Texas. Hopefully her body is found one day, because it might give some rest to her family, but it won't bring her back and undo EA's evil actions, and what happened was done by EA (as it was proven she was IN HIS TRUNK).
