I have no clue how Paladins are supposed to work regarding their tenets and whatnot, but you're basically comitting a crime and grave injustice, while also doing it behind everyone's back. Sazza is a prisoner of war, captured during the attack on it and she is responsible for people dying. The Grove denizens have every right to hold her captive for her crimes against them.
So by freeing her, you're basically not only comitting a crime, but severe injustice as well. Which is why I suppose you're breaking the oath. But then again, I have no clue what the oath is supposed to stand for.
