Man that is a long smoke! Did you have to fire up another load of coals? If so was it a full load or just a starter chimney full?
I did a 5.5 lb. butt Saturday and was expecting it to take around 8.5 hours since it was on the small side (1.5 hours pper lb.). But it took 12 hours which was over 2 hours/lb. and that included the last couple hours at 300 in my dang stove. Guess I need to plan for minimum of 2 hours/lb. next time. I always seem to get the finish time wrong....