Okay, let's get the Werewolf game going:
There were 18 players in total. 1 rebel spirit.
So, the rebel spirit had to choose from 17 players.
The chance of choosing the murderer is 1/17. The chance of choosing anyone else (not the murderer) is 16/17.
1/17 < 16/17 - it's obvious.
Added 1 minute ago
And she doesn't know if she's redirecting the attack to the murderer or not. No questions. I just didn't understand it at first.