There is always something to be said for having a plan B. And NO, I don't mean hot dogs....

I always try to look at things from when you want to eat. it's kinda like a countdown. If we're gonna eat at 5:00pm, then the pork shoulders wil need to be done about 3:00 so they can rest. now count backwards from 3:00 to figure out when you need to start cooking. I always rub up my shoulders with some rub about 12 hours before, so add 12 hours prior to that. For cooking, you might have to take into account you're experience with the charcoal that you are using, the weather, how much meat you have to smoke, how full your BGE is, etc... All of these things will have an effect on your cooking time, assuming that you are holding a good temp in the egg. So, If I want to eat at 5:00, I will need to take a good look and make a decision about mid morning. If temp is now close to the 180 degree range, then Bob's your Uncle and you can take em off at 3:00 and wrap in foil and put in an insulated ice chest. However, if at say 11:00 I have an internal temp of 170 or below, I really haven't plateaued yet, and it is decision time. Crank the heat? yes, this will work, but Murphy still has some say here. If I'm faced with this decision, I'll take em off, wrap in foil, and put in a 250-300 degree oven, where a couple of things will happen. 1. you'll continue to cook, and 2. the steam will be trapped by the foil, aiding with the desolving of the colagens. at the desired temp, turn the oven off, and let it sit there, or move to an insulated cooler. This will NOT affect your finished product. Once you pull it, you'll have a hard time keeping everyones fingers out of there anyway.

I will always have be ready to eat when the appointed time comes. Nobody will leave my house hungry. and it will be great.

The point is, there are other techniques that will make you successful. In your case, maybe it was a faulty temp probe. I keep an instant read on hand for that purpose. or maybe it just wasn't ready using the technique you were using. Then it is time to change the game plan just a bit, to get ready for your 5:00 dinner. You can do it. just pay attention to what is going on through out your cook, and make the adjustments.

Murphy does not come to my house anymore, because I always have a plan B or even a plan C. He tries to crash the party once in a while, but has not been successful.

Take what you learn every time you cook. apply to the next time and the next. You'll have this down in no time. It is pretty hard to fail using the BGE, but one thing is constant, you'll always learn something.