Les should stop allying with Todd Standing
Look, everyone deserves second chances, I'll just say that up front so this isn't taken as an attack on Todd. I don't know his full history but Les freely admits his reputation is "dubious". That seems like really shaky ground to begin an investigation on. Assuming Les did find strong evidence it would be slammed for having any connection with Todd, who apparently has been accused of hoaxes in the past. This first true evidence is the most crucial so it's important to not have any extra stigma attached to it.
What Les needs to do, and I don't know why he doesn't, is go into an area completely unannounced and spend his nights. The fact he went camping with Todd and then did a night solo opens up too many "what ifs". Sure, Todd could have gone back home that second night, and even if you can prove it, what's to say he didn't tell people ahead of time to go out there and take the apples or make sounds on his behalf? Again, I'm not saying Todd did any of that, but when you're working with a guy with a reputation of potential hoaxing there will always be that fog of suspicion surrounding you. Les knew of that camp site from last year, and he certainly didn't need Todd's permission to go back, so why inform anyone? Just go up there on a random night and see what happens. That would cut the potential for hoaxing down to nearly zero since I'm sure not many other people would be roaming around up on that peak, and especially not with the intent or equipment needed to hoax.