[Inziladun]

Gandalf makes it clear that Gollum is to be pitied, but he does not offer him absolution.

He said to Frodo that the prime reason Bilbo had been able to resist the Ring's influence as long as he did was because he had begun his "ownership" of it with pity and mercy, not killing Gollum. Bilbo, though of the same kind as Gollum, had a very different reaction to choices given him when the Ring crossed his path. Bilbo could have easily killed Gollum, destroying the one witness who could ever have contradicted any story Bilbo chose to concoct. But he did not, and character must be the answer why.