I've alll ready had some spirited debates about this on some other boards, so I'll keep comments brief here.
Yep, it's perfectly legal for the Pilatus and the Premier to roll through GLAD/BAG MOA. Not very smart, and a real dick move which had a more significant impact on military training than they realize...but totally legal none the less.
The Viper driver had no reason to go actually intercept the two airplanes except to send them a message that "we're here!". I suspect the real reason is that on both occasions the F-16 guy was going to VID the tail number of the Pilatus and the Premier, but that's just speculation on my part. I've been similarly pissed when civil traffic has gone through a MOA I was working, and thought about doing that several times, but never acted on it. So long as he obeyed the "well clear" rules, he was legal to do it (regardless of what the TCAS RA "made" the Premier pilot do). If he was intentionally inside of "well clear", then he's clearly violating some rules and should be reprimanded.
The "10 feet" report from the Premier pilot is ridiculously unreliable. The radar data from both the ground radar and the F-16's on-board radar show otherwise. Besides, it is TOUGH to accurately tell distance while flying, and an angry/surprised/startled pilot who is not used to seeing other aircraft flying close to him would be highly susceptible to either exaggeration of the distance or misperception of the distance.
The F-16 driver knows exactly what 500 feet from another airplane looks like (it is an 11-214 Training Rule for air-air combat) and practices it often against many different types of aircraft. The F-16 driver also honors that 500-foot bubble religiously because of the legal implications of going inside it. I doubt with every bone in my body that the F-16 guy was inside of 500 feet. However, that doesn't mean it didn't happen. If evidence arises that he WAS inside 500 feet, then I'll be the first one to say that he was wrong.
Yet again, this incident shows the massive ignorance the civil and military flying communities have toward each other. Many civil pilots seem to think that their "legal right" to fly through a MOA means they ignore when it's hot to save some time and bucks, and have a huge impact on military training. Many military pilots have little or no experience as civilian pilots, and think that they own the skies, neither desiring nor knowing how to play nice with others.