Seeing as the difference between A and S rank is usually something like, A ranks can destroy large cities, and S ranks can destroy entire countries, not sure how they can blame the only, A RANK, adventure that just happened to be there to witness it. I'm assuming there will be a plot point later that proves that the dragon woke up due to something else entirely thus "clearing him" of causing it, not terribly interested in seeing that kind of thing again, I'd rather see the girls defeat and kill the dragon later on when they grow up.