I feel obligated to ask why you were talking about "time to prepare" two pages ago, and you said "what took [the dragon] so long" which implies the dragon actually took time to get to the inn, but you really only gave us what amounted to a couple of IC minutes. What was your exposition going to be in the first place anyway? 

You also seem to have flat-out ignored what preperations there were and on top of that the 40-foot-tall dragon has apparently stealthed past the paladin and the ent or teleported into the clearing or something given how nobody saw or heard it coming until it was already practically in the clearing.