[QuantumIguana]

He's an ambitious noble. One of the time-honored ways of obtaining a crown is to pluck it from the lifeless head of the previous owner. Whether that is considered to be bad or good depends on your perspective viewed from the perspective of the current owner of that crown. The usurper who failed, there's a villain for you. But the usurper who succeeds, and builds a dynasty, there's a hero. The witches just give Macbeth a little nudge. Macbeth thinks he is the master of his own destiny, but he is the pawn of others.

What you learn is to pay very close attention to the details, because there apparently is no appeal. You need "Birnam Wood" defined, and what it means for that wood to come to Dunsinane. I would say it hardly counts just because some wood came from there. The capital makes all the difference: "Birnam Wood" refers to the forest, while "Birnam wood" would simply refer to some wood that just happened to come from Birnam. But it was an oral contract, which isn't worth the paper it was printed on. And does "of no woman born" really eliminate those born via C-section?

I think that the battle should have stopped right there for an appeal. Set up a little courtroom before things go any further. "Your honor, my client contends that even if this wood did indeed come from Birnam Wood, that fact does not constitute Birnam Wood itself coming to Dunsinane, and in addition, it has not been established that the aforementioned wood in fact had its origin in Dunsinane."

Beware of rhetorical flourishes. There may be loopholes hidden there.