GRRM is asked about Sansa misremembering the name of Joffrey's sword
George R.R Martin:
The Lion's Paw / Lion's Tooth business, on the other hand, is intentional. A small touch of the unreliable narrator. I was trying to establish that the memories of my viewpoint characters are not infallible. Sansa is simply remembering it wrong. A very minor thing (you are the only one to catch it to date), but it was meant to set the stage for a much more important lapse in memory. You will see, in A STORM OF SWORDS and later volumes, that Sansa remembers the Hound kissing her the night he came to her bedroom... but if you look at the scene, he never does. That will eventually mean something, but just now it's a subtle touch, something most of the readers may not even pick up on.
