I’ll address a couple of points.
1. Campers don’t “borrow” vacant spots that are paid for by other campers. And this was a crowded campground. Occupied sites have some indicator that they’re occupied.
2. It seems neither site was vacant.
3. We don’t know if the emty parking spaces were empty so kids could play.
I have been at a campground where toddlers were racing each other on Strider bikes! (Little bikes with no pedals) they were zooming down a slight incline on the loop road. At any rate, it would be normal for even little camping kids to play on bicycles; plus, the Malibu campground was flat with easy site lines from many directions. (See the link I posted upthread with photos of every site.) #49 and #51 are about as open as you can get.
There are typically bicyclists big and small in campgrounds: the speed limit is generally 5 mph. Drivers are careful.
4. As i mentioned upthread, the victim was an experienced and meticulous camper. Just look at how tidy and taut that tent is. Anything with any aroma (food, dishes, coolers, etc) looks to have been placed in the car (to discourage animals). There is not a suspicious reason for these details: they are the sign of a thoughtful and knowledgeable camper.
5. I’ve only seen one tent in photos. I don’t believe we’ve seen the second tent.
6. Personally, I like my car near the picnic table. Also, if I’m using a tent. Much easier to load and unload the car. BIL’s car might have been parked next to the victim’s just because both families had meals at the same picnic table. Also, the parking spot for the second site might have been at the far edge, i.e. not compatible with sharing a picnic table.
