Why??

I am very disappointed with Code Geass plot twist in s.1 ep.22, where Lelouch suddenly uses geass on Yuphimia and she orders to kill the japanese.

My feels are based on 2 facts:

1. It is a monumental plot twist that puts everything upside down.
2. It is a completely random unpredictable event.

Code Geass was meant to be a show about strategic thinking and the fact that the main plot twist was not a result of actions of some characters, but just a random thing,blows my mind.

I'd add some examples from other shows, but then no one would read it bc of spoilers.