Dang, I definitely don't want to break his oath. But I also usually don't sneak around murdering people, so maybe it will be fine. Thanks guys.
As long as you don't attack any characters that are yellow instead of red, it seems to be fine. There's also usually a cutscene option to initiate combat for most of these situations, which doesn't count as oathbreaking unless you attack without provocation.
I'm at the end of Act 1 with my Ancients Paladin and have had no issues maintaining my oath.
