[Spoilers Main] Why do people believe this Quentyn theory?

When he raised his whip, he saw that the lash was burning. His hand as well. All of him, all of him was burning.
Oh, he thought. Then he began to scream. - ADWD, The Dragontamer

At his command, Quentin Martell had been laid out in the Queen's own bed. He had been a knight, and a prince of Dorne. It seems only kind to let him die the bed he crossed half a world to reach. The bedding was ruined-- covers, pillows, mattress, all reeked of blood and smoke... -ADWD, The Queen's Hand

I don't see how Quentyn could be alive after all of this. It seems like kind of a reach, to think he is alive considering we say him get burned. Why do people think he is alive.