Ah, okay. I'd stopped reading about the time the President sacrificed himself (apparently pointlessly). Which in context I don't think was long before that.
Well the Chimeraant arc was stupid over all though it had one or two good moments. The technique Gon used made him forcibly age many years until he reached his full power (which is referenced here by the model number I guess). Page 16 is actually also part of the reference since it's what Killua said afterwards (mor or less)