I don't claim certinty about HF. So I'm not sure and can't really discuss it in detail further.
About RoS it means that they can only start shooting then they find someone already shooting to each other. For example:
1) RoS meets a Sair. As long as RoS is not shot upon, he can't start a fight first.
2) RoS confronts a sair and an outcast already fighting each other, he can intervene.