Gandalf Vs. The Witch King

[Boromir88]

But I don't see the logic of interpreting film events by reference to book history that does not feature in the films. The films are adaptations only - they tell a different story to the book.

SpM, it's not that it's different from the book, that gets me irked. Just that when looking at it from a film judging perspective, it doesn't hold unity, that Gandalf can fight off 5 Nazgul (although they were weaker), and defeat a Balrog. Come back stronger (if not physically then mentally), after slaying the Balrog, then get owned by the Witch-king.