Thank you for this well thought out, and logical post.
What you describe aligns with RT's speculation that someone abducted his wife.
However, while anything is possible and the outcomes of our threads never cease to amaze and surprise me, I don't see this possibility as highly likely.
While a woman clad in a bikini would catch interest, grabbing a 5'9" woman wouldn't be that easy, unless at gunpoint....which is a possibility. A gunpoint abduction is the only scenario that would make sense in this theory. OR, she might have been angry at RT, and decided to hitch a ride back home, and something went awry. My friend who knows Bullhead well describes it as being somewhat "outlaw". People carrying guns would not be unheard of.
The above stated, I still believe Barb is like Paul Miller....out there, yet to be found.
Amateur opinion and speculation