Sorry I can't help with a reference, not being a "respected professional" (at anything, really).
But I have to wonder about a couple things. When you say "taking control of" you mean physically grabbing a gun you are wearing or holding?
I'm no legal beagle, but doesn't that constitute assault? Possibly Assault with a deadly weapon?
Would not a reasonable and prudent person believe that someone who tries to take a loaded gun from you (by force) is doing so, so that they may use the gun? And since you are right there, doesn't that put you at the top of their potential target list? Seems like a deadly threat, to me, but then, I'm no expert.
Orders to put the gun down, etc. from uniformed, and/or identified lawful authority are one thing, some guy grabbing at a gun on you or in your hands quite another.
Personally, I'd put it on the same level with someone pounding your head into the pavement. At that point, HOW the situation came about is irrelevant. What matters is you are being attacked, and deadly force is already in the mix.
I'd call it a no-brainer, but as we have seen, time, and time again, other people can see even the clearest things in a different light than I do.
All else being equal (and it almost never is) bigger bullets tend to work better.