I think context is everything. I cook on an offset. So using the green wood during the heating up stage i.e. burning wood to preheat my pit makes sense. Even if it doesn't give an off flavor, making greenwood into coals is a royal pain in the arse. It takes forever to burn and your temperature in the pit gets inconsistent if you're burning green wood all the way thru.
In a charcoal smoker like what Myron Mixon uses, that's a different story. His wood is for flavor alone and there isn't that much of it to make a significant difference because he has his lighter fluid pee'd on charcoals to support it.
If you're cooking old pit style then it really doesn't make a difference as you're burning the wood down to coals to begin with.
So it's not that Myron is "breaking the rules", he's just using what's good for his cooker.
Bubba Grill Super Cooker. Bringing Carolina Whole Hog BBQ to NYC www.arrogantswine.com