If Max fell off the balcony, grabbed the chandelier, and then fell to the floor...how, indeed, did the scooter land on top of him? Even if he did somehow go over while riding the scooter, the scooter would've hit the ground first because it, presumably, would have been dropped when he grabbed the chandelier. I can't make the scooter work with the chandelier.
Regarding Rebeca being at fault...as the parent of 2 young kids, I certainly wouldn't blame JS or DS for blaming her in their grief (and we don't know that they did). That said, while I do think Rebecca was responsible for Max at the time, since she was the only adult, I don't believe she was to blame for his death- they're 2 separate things to me. We simply don't know enough about what happened. What if Max was playing quietly in his room, Rebecca went to the bathroom, and then he zoomed down the hall on his scooter? How is that her fault? It's my understanding that this could have happened instantaneously and I just don't see what she could have done, even if she had been present. This is, of course, assuming he wasn't planking or engaging in some drawn out horseplay near the stairs. But I can certainly see how he could just happen to head for the stairs in the minute or two she was in the bathroom and I can't blame her for that. It's not as if he drowned in the backyard pool, meaning he was out of her sight for several minutes. This was a freak, instantaneous accident that I doubt anyone could have predicted or prevented.
Rebecca's message is haunting me. It's eerie. She (assuming she wrote it) had to know Jonah wasn't going to be home in time to save her, if Jonah is the "he" in the message. She had to know the chances of anyone saving her were slim. It almost seems taunting to me, as if someone else wrote it to Jonah about how he couldn't save her.