If you aren't a paladin, you can say the exact same line, which is tagged deception, and as far as I've seen, that counts as lying for the purpose of breaking your oath. I personally think that particular line should have two options for deception or persuasion, because both could be applicable in that specific case.
My issue with that whole sequence is regarding the draconian method of determining whether or not a paladin breaks their oath. Gently misleading someone to try and defuse a situation that is quickly turning violent should not count, but it does, but instead of changing the method to be less strict and allow for such situations, they put in a special allowance for paladins that is no different from the regular deception option. The fact that that's even in there means that someone realised that their strict judgement on oaths would cause problems in some places, and I really hope it gets changed before release.
Hold up, hold up. Let's just clear the PFH situation.
Swen did not use the [Paladin][Deception] tagged line. He picked the line that said to the Tieflings to get Lae'zel down so they could all then kill her (!) Then proceeded to betray the Tieflings (!!) and kill them (!!!).
(Sorry, I muddied things by talking about my playthrough.)
I'm not familiar with Paladin of the Ancients, I've put their tenets in spoiler below, but struggle to pinpoint what specifically was the main violation. Certainly there wasn't much mercy, nothing beautiful, not much delight and much to despair of. If I had to say, it'd be the manner of the killing + the killing itself.
Kindle the Light. Through your acts of mercy, kindness, and forgiveness, kindle the light of hope in the world, beating back despair.
Shelter the Light. Where there is good, beauty, love, and laughter in the world, stand against the wickedness that would swallow it. Where life flourishes, stand against the forces that would render it barren.
Preserve Your Own Light. Delight in song and laughter, in beauty and art. If you allow the light to die in your own heart, you can't preserve it in the world.
Be the Light. Be a glorious beacon for all who live in despair. Let the light of your joy and courage shine forth in all your deeds.
