Sophocleese said:

Why have the characters wobbling around forever on a piece of crumbling masonry?

"Forever", indeed! I thought they'd never get on with the story, and for an incident that didn't even advance the plot. I'd have to look at the book again, but I don't recall anything at that point that could even give an initial basis for the crumbling-masonry scene. And not very believably done, either. A case of a screen writer wanting to leave a personally desired Disneyish mark instead of picturing Tolkien's story. Bah!

Dave Oesterreich