Det finns detta från böckerna wiki :
Quentyn's companions are keen to return to Dorne but Quentyn refuses to go. He does not want to return having failed.
He hatches a plan, hoping that he will be able to tame at least one of the dragons due to his Targaryen ancestry. For this purpose, he arranges a meeting with the Tattered Prince, hiring the Windblown's help in seizing Rhaegal and Viserion. The Tattered Prince agrees, asking for Pentos in return. Quentyn signs an agreement.
Dressed as Brazen Beasts, Quentyn and his companions go to the pit where the dragons are kept. The Tattered Prince had given them the code word to be used by the Brazen Beasts that day (dog), but with Barristan Selmy's coup occurring at the same time, the Brazen Beasts guarding the door are not aware of the code word.
Gaining access to the dragons, Quentyn eventually attempts to tame Viserion, but Rhaegal attacks Quentyn from behind, and bathes him in dragonfire. The Windblown mercenaries flee, and both dragons escape.
Missandei takes care of Quentyn, but he dies in Daenerys Targaryen's bed four days later, covered in burns. Upon seeing the extent of the prince's injuries, Ser Barristan thinks it would have been better if Rhaegal had just eaten him alive, as his death would haven been quicker and less painful in such a case.
Det motsäger, men kan innebära att Tyrion bara har mycket tapperhet trots sin lilla storlek. Quentyn trodde att hans blod var tillräckligt, medan Tyrion har det förtroende att tämja dem.
Det är verkligen ingen mening och är inkonsekvent med boken, så vem vet verkligen? Dålig berättande kanske.
TLDR; En möjlig teori är att drakarna kände igen Tyrions självförtroende och respekterade det.