Is there any reason to believe that the guy James supposedly played pool with would not have been involved? For some reason, I'm suspicious of him... I don't know why, maybe I just haven't read enough.
But, if I recall correctly, it was claimed that James and Pam had stopped at the KOA on their way to Florida. Again, if I recall correctly, supposedly James was asked how they liked Florida and he supposedly said he liked the Sumter area better.
So, here's a few of my thoughts... If they stopped at the KOA on their trip to Florida, this might have given someone an opportunity to expect them back on their return trip. Meaning, if they appeared to have lots of cash, or if he played pool for money and lost and couldn't pay up, then the return trip gave someone the opportunity to get back at him.
Also, it bothers me that they had no ID on them when found... AND when Verna went to do some of her own investigation, the KOA records had been destroyed in a house fire. Just too coincidental for me.