Sarin shrugs and says to Shay, "I don't know who my Keeper is."  He then nods and says to her, "Yes, once a dragon and their Keeper are bonded, if the Keeper dies, so does the dragon, and I believe it works the other way as well....but she would know more about that."  As he said the last part he nodded to Mira.  And then when she commented on his height he says her, "Yep."