I'm no English professor, but I can expound anyway. And since I've been
commenting on the writing throughout this chapter, I don't need to say much. :)
I DO remember my first reaction to this scene. Absolute shock and blank horror.
Not only was Gandalf supposed to be invulnerable (in my 11 year old mind), but
the writing itself had built up to just this part -- an incredible climax.
This paragraph is punctuated just as it should be, and that is Cinematically.
Tolkien wants us brought up short at each action of Gandalf's. Each action is a
miniature climax and we should feel each one as a separate literary punch in
the gut. He staggered. Fell. Grabbed. Screamed. Slid. And was gone.
You know, Tolkien is more than good at these climactic paragraphs -- he's
brilliant! Witness the amazing writing at the conclusion of Flight to the Ford,
or of course the clincher, Mt. Doom. This is one of the Big Reasons that I just
love this book.
CHALLENGE: oops, don't have my book with me right now, big mistake, because the
only other "fool" speech of Gandalf's that I can remember off the cuff is of
course the immortal "Fool of a Took!" Gee was I glad that this found its way
into the FotR movie. But Gandalf loved to level this charge at his friends, so
I'm sure there are other instances. (I'll now take a peek at others' answers to
see.)