Allright, went digging on me own, and apparantly, there was a bug that allowed 53s to drop from him but it has since been changed.
I noticed that the person who said he had 53s was from one of the supergroups that had the earliest hands in defeating hami.
Scuttlebutt also informs that they work identically as 50 HOs.
Anyway, a curious tidbit of hamiO trivia to be sure.
cheers