Well, that's a plausible explantation, too. But I for my part can't really say that I share your point of view, that may be due to my love for Killuah's unique personality. Especially the merciless part of his personality and I don't think that his behavior in this episode was fitting in with the meaning and the chapters theme at all. Because Killuah is still kinda new to the group this cruel move was to show that he's no child you want to piss off, since Leo and Kurapika had no clue about Kil's abilities up to that point, therefore they were astonished about the heart-removal-thingy =3
And as I said I'm not angry or something like that, but I will be pissed off like hell if they're going to f**k up some major scene's meaning or something worse, because the Animation Studio should know the Mange they're adapting. I'm positive that they will do a good job though it's mad house we're talking about here after all *~*
I just hope they forsee possible problems with upcoming violence in major story events. =)
I like how you interpreted Kil's merciless, though
I'm looking forward to the Hunter Exam's Final Stage, sucks that we have to wait a little bit for the next episode, but I guess it's worth waiting for.