What would be the motive for stranger abduction? Steal a housewife? Seems way too far fetched for me. Possible, yes. Probable, nope!
I'm almost to the point of ruling this out as any kind of reasonable possibility even (and, at best, it's highly improbable, IMO). At this point, to believe BM to be innocent, I think you'd have to believe he's both the luckiest and unluckiest man alive.
So incredibly lucky to have the CCSO involve the CBI and FBI almost immediately on this case - wow, so many professional resources to help solve the case! But, unlucky for BM, he happens to get the "bumbling idiot" division of these three agencies who are only effective at messing up crime scenes, lying to people, and framing innocent husbands to cover up their ineptitude.
So unlucky that he happened to be out of town at the time SM was abducted on her "bike ride". But so lucky that he happened to have an urgent job come up on a holiday weekend three hours away, so at least he had a great alibi that could allow LE to rule him out immediately and focus their efforts on finding that @#$% mountain lion.
So lucky that BM had witnesses who could help account for his whereabouts on Sat and Sun. So unlucky that they happened to be meth heads who can't be trusted.
So lucky that SM was active on FB late on Saturday evening, proving she was alive at that time. So unlucky that whatever "SM" was doing on FB that evening was highly unusual for her and suspicious to all of her friends.
So lucky that he has such a potential ally in AM, a loving brother who desperately wants to find his sister. So unlucky that AM is more concerned with "publicity" and "blaming the husband" than looking for the mountain lion.
You get the idea. One or two of these things you might chalk up to luck...... but the list is waaaay too long to ignore (and I think LEs list is much longer than ours). MOO, JMO.