George R. R. Martin foi questionado e explicou que estava negando direito a Tyrion.
Another subject was guest rights. He mentioned the time the Tyrion came to Winterfell and Robb met him with bare steel across his lap. That meant that there was no guest rights for Tyrion.
So Spake Martin, ARCHON MEETING (OCTOBER 5-7)
O direito de visitante nos Sete Reinos não é muito respeitado hoje em dia, exceto no Norte e no Norte verdadeiro. Afirma que nenhum dano chegará ao hóspede.
One notable custom that the Northmen hold dearer than any other is guest right, the tradition of hospitality by which a man may offer no harm to a guest beneath his roof, nor a guest to his host. The Andals held to something like it as well, but it looms less large in southron minds. In his text Justice and Injustice in the North: Judgments of Three Stark Lords, Maester Egbert notes that crimes in the North in which guest right was violated were rare but were invariably treated as harshly as the direst of treasons. Only kinslaying is deemed as sinful as the violations of these laws of hospitality.
The World of Ice and Fire, The North
Então, embora ele não esteja dizendo a Tyrion que ele não pode ficar em Winterfell, ele está dizendo que ele não será protegido durante sua estada lá.