MOO
I believe Saturday, after GS had his accident which resulted in some blood-spill plus whatever else occurred that day, TS needed to address what happened so that it would not result in the family being booted from the house and TS wouldn't end up divorced.
I believe the Sunday hike was her initial plan, that GS would have an 'accident' during the hike but she either didn't find the opportunity or couldn't go through with it at that moment: GS' sibling was there, other people may have been around, etc. At that moment, TS new she needed a new plan.
Overnight, a new plan was hatched:
-Call the school; 'GS won't be in today.'
-Tell GS he may stay home from school because of his injury.
-Tell GS to get dressed for the 'shopping trip'.
-Leave for the trip. Scout locations.
-Return home.
I'm stuck at this point because I still am concerned with the 'shadow' in the RD video.
So, the only solution I could come up with is TS picked up GS' sibling from school and THAT who exited the truck?