During the fight, High Justice Grimstone used Pursuit of Justice 1 on himself, even though the skill clearly says: Give another friendly character +2 attack and immune this turn.
My guess on why this bug has occured is because of the treasure siphon soul (Start of game: steal 3/3 from all enemies) from sylvanas. Because of it, both Participating Dark Iron Spectator (3/100 Windfury) have 0 attack. They won’t trigger any action.
Thank you for your time.