: : Pippin mentions that he thought that treebeard had seen him earlier.

This is the same Pippin that later steals and looks into the palantir. At this point and speculation on the part of Pippin, is at the very least suspect.

: That's exactly my point. Only I believe that Treebeard did more than 'see' Gandalf.

[snip remainder]

I don't believe this is the case.

Treebeard had no idea that Gandalf had "fallen out of the story" nor that Saruman had turned traitor until he speaks with Merry and Pipsqueak . . . err, Pippin. ;)

Obviously Treebeard knew of some of the machinations of Saruman, as he is aware that "[Saruman's] orcs are felling trees" on the edge of Fangorn. But it is obvious that Treebeard did not know the entire truth of the matter, and that is took Merry and Pippin, as Gandalf says, "like the falling of small stones" to give him a reason to call the Entmoot. While Gandalf may have guessed at the nature of the "first rumblings" that would be the rousing of the Ents.

-RR