I am somewhat surprised that you could get the point to 200 degrees that quickly, even at those relatively high temps. When I do a high temp cook, it usually takes me ~ 4 hours at 300-350 to get to 160-165, then ~ 2 more hours in the foiled pan.
What was the internal temp when you put it in the pan and covered with foil? I would recommend 160 to 165.
Did you put any liquid in the pan? I would recommend ~ 1/4" of water or beer.
What was the temp in the flat when you pulled it?
Are you sure that the thermometer you used to check the pit temp is accurate at grate level?
30" x 60" Double Lid With Firebox on Trailer
Lyfe Tyme - 16" x 40" Single Lid With Firebox
3 Weber Kettles