Idk about a punch to the face specifically (that sounds likely to cause injury) but a small pain inflicted as retaliation for being wronged does not really seem all that terrible to me?<p>Especially if there is a social convention for how it is to work.<p>Of course, the amount of pain would have to be significantly less of an offense than what it is prompting it.<p>But when pain is sufficiently small, I think the meaning behind the pain is more important than the actual pain.