Bem feito @Shevliaskovic, eu pensei que era a única pessoa que pegou isso.
Mas há também o fato de que Gollum nunca jurou servir Frodo, ele jurou servir ao Mestre do Precioso:
‘Down! down!’ said Frodo. ‘Now speak your promise!’
‘We promises, yesI promise!’said Gollum. ‘I willserve the master of
the Precious. Good master, good Sméagol, gollum, gollum!’ Suddenly
he began to weep and bite at his ankle again.
E sabemos pelo Silmarillion que:
Then Ilúvatar spoke, and he said: `Mighty are the Ainur, and mightiest among them is Melkor; but that he may know, and all the Ainur, that I am Ilúvatar, those things that ye have sung, I will show them forth, that ye may see what ye have done. And thou, Melkor, shalt see that no theme may be played that hath not its uttermost source in me, nor can any alter the music in my despite. For he that attempteth this shall prove but mine instrument in the devising of things more wonderful, which he himself hath not imagined.'
Portanto, não seria uma ironia se, como indica esta passagem, o 'Mestre do Precioso' não fosse Frodo, nem Sauron, mas o próprio Iluvatar? E isso absolve Gollum, de certo modo, porque no final ele serviu ao propósito de Iluvatar, um objetivo que Gandalf previu.