When asked about this discrepancy George R. R. Martin simply said that Sansa is an “unreliable narrator” This has led to much speculation by fans on what he means and intends. One thing is certain, for reasons known only to Sansa Stark, she remembers a kiss.
Sansa eventually arrives. The Hound is very drunk, drunker than she had ever seen him. He offers to takeSansa with him as he intends to flee the city. He mentions going north somewhere. She refuses. He pushes her on her bed holds a knife to her throat and drunkenly demands that she sing him the song that she had promised him earlier. She sings, but not the song of Florian and Jonquil. Instead a terrified Sansa sings the Mother song:
|“||“Gentle Mother, font of mercy,save our sons from war, we pray,stay the swords and stay the arrows,
let them know a better day.
Gentle Mother, strength of women,
help our daughters through this fray,
soothe the wrath and tame the fury,
teach us all a kinder way”. 
The Hound falls silent and Sansa gently touches his cheek feeling the wetness that was blood and the wetness that was not blood (tears). Shortly thereafter he gets up, rips off his bloody white cloak, and leaves. Sansashakes out the torn and bloody cloak and huddles beneath it shivering. Ser Dontos eventually arrives to tell her the city is saved.
Afterwards Sansa comes to remember this scenario slightly differently, remembering that the Hound also kissed her.
All of this was borrowed from http://awoiaf.westeros.org/ <–Great site!!!