I agree with the interpretation that the bonuses would not apply while a hero is at 0 hp.
Leaving aside thematic explanations, which can go either way, heroes are generally treated as if they're just not there while at 0 hp: monsters ignore them, they are not affected by encounters, etc. Therefore I would posit that the hero is also "not there" in the sense that he cannot impart bonuses to comrades.
Leaving aside thematic explanations, which can go either way, heroes are generally treated as if they're just not there while at 0 hp: monsters ignore them, they are not affected by encounters, etc. Therefore I would posit that the hero is also "not there" in the sense that he cannot impart bonuses to comrades.