There are limits to where experience can take you. For example, I've never slept in a tent with two other guys guarding an 160-acre marijuana field in southern Oregon with 8,918 marijuana plants. Or at least I'm not going to admit that I have. Nor have I, while sleeping in such a tent, had a .45 semi-automatic pistol on my sleeping bag alongside a rifle and other firearms in the tent. So I admit that my particularized experience in this area is not totally on point.
But, still, I don't think it's hard at all to conclude -- as the Ninth Circuit does here -- that even though there's no hard-and-fast "evidence" that the guy lying in the sleeping bag (as opposed to either of the other two guys) was the one who "possessed" the .45, and similarly no absolutely conclusive evidence that he was using the gun to guard the field (as opposed to, say, just target shooting), I can still say with extreme confidence that both of these facts are true. Even with my lack of personal experience in this area. We all know that you possessed the gun and why you had it. And when the jury convicts you therefor, your argument on appeal that you should be acquitted based on insufficient evidence is not going to be persuasive. Not to Judge Ikuta -- who authors the opinion -- or pretty much anyone else either.
Yes, technically, there might be an alleged "deficiency" in the direct evidence, and I understand the argument that there's no proof beyond a reasonable doubt. But the law ain't blind. Neither are juries. Hence the result here.