All just my opinion.
Quite honestly, I have seriously considered the possibility that Joe walked into a testing range. He wasn't in military gear. He was in civilian clothes. He very likely would have gotten shot. They may have admitted their mistake... or may not.
I'm sorry, but unfounded accusations aren't productive. They really don't go running around, willy-nilly, shooting intruders out there at Dugway. It's not Area 51 (and Area 51 itself isn't what the conspiracy buffs portray).
In the past ten years, there have been three heavily-publicized "intrusions" at Dugway, Tooele's nerve gas disposal area and Hill AFB. They are handled by locking down the bases, and searching for the intruder. At Hill AFB, a guy even rammed his car through the main gate - and no one shot at him. The base police searched several hours, until they found him crouching in a culvert.
The entire complex (Dugway Proving Grounds and the Air Force's Utah Test and Training Range) is fenced. That's why there are gates.
A soldier walking up to a manned gate would not be shot. He'd be walking up and asking for help. Why would they shoot him? They don't shoot my husband or son-in-law, when they drive up to a gate at Dugway.
A soldier could not enter an unmanned gate, unless he had a key. If he had attempted to climb up over the barbed wire, it would have been noted.
Like a General told me once: "The military isn't good at babysitting."