defend ally = negative rep with ally?

Flyingpopcorn#1279

I joined a war to defend my defensive ally "Wardens of the Living Pools" against Bordeleaux.

Result: Wardens of the Living Pools condemns: War with Bordeleaux -3 rep

This has to be a joke?

GloatingSwine#8098

It's an unexpected outcome because the diplomatic relations for actions against factions are sometimes hardcoded and not related to how the actual faction relationships work.