I know we treated him as a ghoul, but not a Necropolis one. He may have been irradiated before or after. All I remember was that he went in there with the guy whose name I forget (the one who fell into the vat and became the Master), and only Harold came out. Harold's memory is totally whacked, btw.
...most people don't know when they get irradiated, so he [Harold] just may not know what happened to him. I do know that radiation and FEV do not mix. Mutants are immune to radiation effects, but an irradiate human is killed by exposure to FEV. So one thing is sure: Harold is not a mix of radiation and FEV. He's got to be one or the other, and I think he's a ghoul.