MOO I agree that all of that could be possible. I agree that the idea of flying home is not at all odd and/or nefarious. I follow a few vanlife channels and a boatlife channel and have seen some of those people fly home in the middle of their adventures.
I had another thought last night about the Moab murders. Until last night I had been thinking about it only in what the connection between the two could have been, if any, but the thought occurred to me that neither of them might have heard about it until after BL had flown home. Being a male, he might have just shrugged it off as not relevant to them, but women don't shrug off stuff like that. She might have begun thinking about ending the trip out of fear of a serial killer on the loose. 2 men had also gone missing in that area in the last month or two.
So here comes back Brian, all fired up to continue the vanlife after spending all that money to clear up stuff back at home so they can go another year, but GP is having second thoughts. They start fighting more, and the more they fight the more she may want to quit. Until ... And then he thinks, I'll fix it so I wasn't even here when the "serial killer" got her. Or, alternately, in some unlikely coincidence, it actually happened that way.