I like the article, it's thought provoking, but it is dead wrong. I am a physics major, and this article blows smoke. Pardon the pun.
The reason for the stall is detailed in the thermal equilibrium curve. The higher the thermal mass of your pit, the longer you will experience the stall. Heat approaches equilibrium after 2-3 hours, then slowly approaches the equilibrium over a long time, as the curve graft shows. Once it is achieved, the pit and surrounding can not take in more heat and the meat temp will rise. A few examples. This is why professional pits ( bbq restaurants ) never let the fire die out, you don't have a stall and the meat can be cooked based on time alone. Place a nice large piece of meat in a sealed crock pot, dutch over or ceramic slow cooker. Low and slow on your pit as you normally would, guess what, you get the stall. There should be no evaporative losses when the meat is under water and sealed. But there is still the process of thermal equilibration. Evaporative cooling is based on one main event, that is continuous convection. In order to even consider this theory plausible the airflow through the pit would have to be significant , and much more than any of us would do on a low and slow. The humidity of the pit when the airflow is controlled would not allow for evaporative cooling. You would basically need a full size fan pushing air constantly across the pit and the meat. One last point. The premise of this theory is that when the meat dries out and can no longer provide evaporative cooling, we then get a rise in temps and the pause ends. This would imply all our meat turns out like shoe leather. Try it yourself, low and slow cook anything in a pot of water and the temp curve will always have a pause at 2-3 hours. If, you were to bring the pit temp well above your intended cooking temp ( 350 ) for 3-4 hours prior to initiating your low and slow. Then allowed the temp to fall after placing your brisket in the pit, you would experience no pause. Thermal equilibrium has been reached prior to the cook.