Harper's got amnesia, so if he's involved, I doubt he helped out after he came back, unless he's been faking. I'm not sure he'd be up for it and Rex's been planning this for a while. I don't know McClullen but you're the second person who's said it could be Nygma's fault, and frankly, I wouldn't be shocked if it was.

Well, thanks for indirectly protecting me from getting stabbed in the neck with whatever he's injecting people with. Seriously.