"It seems I've been careless."
Among all the possible answers that Sara expected, the one Desmond gave was not one of those. The young girl had gone to great lengths to create the plans in those documents, and her intention was, of course, to support her Master, but she still wanted even a little bit of appreciation and acknowledgment.
Unlike Natalie, that little manipulator, Sara was an open book, so how could Desmond not notice what was going through the little beauty's mind.
"Don't look so disappointed. It's not that I have a problem with the plans you have here; if I had a complaint, it would be to myself for not realizing how talented you are sooner."
Given her high spirits, Desmond's tone was incredibly kind and warm, enough to snap Sara out of her despondency. Of course, Sara still didn't believe that Desmond was to blame for anything; he was her Master, and the whole world could be wrong, but he never would be, at least not for her.
