you all seem to forget that Gandalf alluded to the fact that the WK was more powerful then him when he was talking to Pippin before the battle of Osgiliath
his facial expression alone would be enough to tell that he is terrifed of WK, not only this but his hesitance or thought process before telling Pippin about the WK is another allusion to this.
Secondly, the scene was one of huge drama and tension, WKs' ability to destroy Gandalfs staff and deseat him from shadowfax is PJs' interpretation of the shear, raw power of WK, the fact that you are irked by a minor injustice done to Gandalf, is in itself an injustice to Peter Jackson.
Thirdly, Aragorns ability to defeat WK in the first film is clearly a foreshadowing of his true abilities/power which is revealed later in not only that film but throughout the trilogy.
One other thing, from my interpretation Gandalf is not the most powerful being in ME, that place being reseverved for Sauron (you can take that as you want, but I am simply alluding to the fact that Sauron was able to create such a device of evil and destruction in the form of the One Ring, and then "Come Back from the Dead" though I do not have words to truely give that a justifiyable explianation)
though Gandalf in clearly the wisest being in ME.
thats just a few things that irk me about most of your arguements,
I am not trying to belittle your opinions just present my veiw on the scene
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