Glad it went well! he is too smart for his own good that one!!
I am also finding though that when things go bad there is nothing to be done but get through it and then do what you did and talk about it out of the moment and then again just before you are about to come to the situation again. What I find positive about it is that although we have huge blow outs then and again, once we have an issue about it and address it, it generally doesn't happen again. KWIM? So in your case we wouldn't have the dinner-dessert issue again. I think thats the advantage with being 3...they can process quicker and remember how upset they were and work out quicker its not worth trying that one again. So at least thats something eh?!
