I think the level of swelling and the reaction one may have will depends on a few things, 1# how long the hog got to chew on the person, remember they are rear fanged venomous and this is a poor delivery system.
2# the person itself, children, elderly and people with weak human system and or allergy history may be more likely to have issues.
Again they are not prone to bite I useally walk by a snake and it wants to bite me, with hognose I never had that issue (7 years and no bite, wish I could say the same with the other species I work with).
I guess one day if I get bit I will have to document it then again there might not be any reaction at all, on the other end my husband is prohibited for handling hognose he has an history of severe allergic reaction to I really do not want to find out what would happen in case one decided to bite him.