Not clu here but, yes, that's what I'd like to know. I'm more curious about if someone mislead JM for some reason or why JM thought Christina was supposed to work on Saturday. A long time ago, a poster suggested that maybe Christina had mentioned she had to work on Saturday to her mom before anything bad happened. Could be that but since mom spoke to the boss, it seems Christina really was supposed to work on Saturday.
Maybe the boss called Christina a bunch of times and got vm. Maybe now she's kicking herself for not doing more earlier to try to reach her. No one is thinking the boss did something to hurt CM, least I don't think so.
What if the boss called one of the group people and was mislead/delayed for some reason. That info would probably be kept under wraps during the investigation imo.
The story the mom believed is just weird. CM was going to spend the night in Plano but then didn't because she had to work on Saturday and needed to see her dog. Both those factors were in place before she decided to leave. Yet mom stated those two reasons for why CM decided to go home at 4:00 a.m. Who fed mom those ideas?