I've been making pretty good pulled pork for years and I've never received complaints, but I've noticed inconsistencies and I'm not sure if I'm missing some cooking "laws".
Generally, I will smoke pork shoulder for about 8 hours being somewhat reserved with the smoke (at about 200F) Then I will transfer to a roaster, sealed with foil, and roast overnight at about 150F until it can be easily "pulled" apart. Sometimes it seems that it stays tight and dries out a bit. This gets minimized with the "saucing" (using a "pig picking sauce" of pepper, salt, and cider vinegar) Am I missing a critical time when the connective tissue breaks down and pulls easily and is still succulent (instead of dry?) or can you just keep cooking pork at a low temp and eventually it will just fall apart nicely?