Just a thought, say hypothetically the "Seller" has nothing to do with this...yes, he might find it odd that they never showed up, and maybe even tried to call them, but their phone would be off...he might not think more of it unless he saw the news reports, which maybe he hasn't...now, when buying and selling on CL there can be a lot of flakes from what I've seen via my friends selling stuff...people agree to come meet and never show up, call...I think that's a big part of it, waiting around on people who never show up...now, do I think this is the case, not likely, but just wanted to mention about flakiness being normal for craigslist transactions.
In Tim Bosma's case, I think stuff went down during the test drive. I'm imagining a possible scenario where Bud and June basically walked right into a trap, maybe at someone's property... Maybe 2 perps, maybe one keeps June hostage while the other goes with Bud to get the money, if he didn't bring cash...I hate to think these scenarios, and I hope the family isn't reading here.