Was Gollum's slip the only way?

[Elianna]

It probably should be taken into the picture that Sam was able to resist the Ring, despite having it in his possesion on the border of Mordor with all hope of Frodo living gone.

Even so, Child's probably right (as usual), about Sam not being able to destroy the Ring.

*thinks about it for a while* Gosh, it does seem rather hopeless with Gollum. He had a part to play, and that was it: to die with the Ring.