Playing the poison pill mission on Legendary difficulty. Defeated a Hell Hound in combat, and the scenario modifier Retaliation (roll 1d6, on a 1 take 1 fire damage) kicked in, rolling (I think) a 5. The game informed me that I then needed to take 5 damage. Not clear if this was due to Retaliation or to the Hellhound's ability (which says it deals 1 fire damage after action) or the combination, but either way it seems wrong.
The other active scenario modifier was Darkest Night, if that matters.