So. If Melissa is telling the truth, then Alison lied about that night. Which isn’t a shock. I actually have a whole post about it from when S4 Finale was shown.
If that’s true, then what was Mrs. D covering up?
What if the story she told was what happened to Bethany. She replaced the shovel with a rock in the story so that it wasn’t identical. Mrs. D saw it and helped protect her daughter. The email she tried to send was for Alison, who she knew was alive. The suitcase she handed off (to Cece, based on clothing evidence) was for Alison.
The only drawback to this theory is that Alison does have a scar on her head. There was scar tissue where she was struck with the rock. Plus then you have to wonder why Mrs. Grunwald would lie about her part of the story.
It’s all very vague and every bit of the story contradicts another part…