Question....Most assume, as you have stated above...She left with GS and came home without him, from what is seen on second-hand video. I too, have viewed this "second-hand" video, and it does appear, while viewing frame by frame in the edit software, that there is a shadow.
So, my question is, has anyone ever discussed the possibility that it was the little sister who was getting out of the vehicle on the other side?
We know from the hike over the weekend that she was with them, we know she was with them during the video/audio of SM questioning GS over the "candle" situation, (as SM was speaking to her in the long version of the unedited video that SM first posted)...
as a side note, I do recall, during the first family interview pleading for GS's return, the little sister (imo) was very nervous and extremely fidgety. She may know a lot...imo.