My gut feeling on CG after looking at his resume is that he is a nobody trying to cash in on his military career despite not having any marketable skills. His bio deliberately leaves out military job title, time in service, deployment information, and rank, all of which is a red flag. We do know he was a junior enlisted in-flight refueler. He touts SERE training like its a special qualification. As far as I know, ALL flight personnel attend SERE (technically all military have to attend "SERE" but for most that's called SERE 101 or SERE A which is a PowerPoint class.) This isn't to knock SERE training. I've heard it's quite terrible. But it's not an elite school. From his LinkedIn, it appears that he's made at least three attempts to cash in on his escape/survival training, including Advanced Catalyst, Project Taken, and something called Palladium. There's not much information on any of them and I suspect they never got very far.
That being said, I don't suspect he's involved. His type (trying to live off the auto-hero status of being a veteran despite not actually having done much in their military career) are a dime a dozen. I think he's just someone trying to insert himself into a case that happened to come up in his community in order to gain attention. Has KP or any of the family actually mentioned him since SP was found?