A Bomb Fell This Shabbos - Details Below

The gemara [Shabbos 132] learns from the extra word וביום in the pasuk וביום השמיני ימול בשר ערלתו that even on Shabbos one may perform a bris milah. From here the gemara learns that even though the act of bris milah is a קלקול because we take a healthy baby and remove some flesh and normally we say כל המקלקלין פטורין, the melacha of חובל [wounding] is different and even מקלקל is חייב. If מקלקל would be permitted with respect to חובל we would not need a pasuk to permit bris milah on shabbos as it would be permitted as a מקלקל. We are forced to conclude [a form of religious coercion...] that מקלקל is חייב in חובל. [There is another opinion in the gemara that ברית מילה is a tikkun and that is why we need a pasuk to permit it].

At the shabbos mevorchim tisch on leil shabbos the Rebbe Shlita dropped a BOMB. The gemara learns from that very same pasuk a different limmud. The pasuk concludes ימול בשר ערלתו and the word בשר is superfluous [if it would have said ימול ערלתו it would have been perfect]. From here the gemara learns that even if the מקום המילה has tzaraas on it and the father intends to cut it off [which is normally forbidden] - he may still do the bris. בשר - even if it has tzaraas.

The question is that we can apparently no longer derive that with respect to חובל a מקלקל is חייב. Since our pasuk is talking about someone who cuts off the ערלה which has tzaraas on it, which is clearly a tikkun, we need a pasuk to permit this tikkun. But really when there is no tzaraas we don't need a pasuk to permit milah on shabbos because it is מקלקל and כל המקלקלין פטורין!! So how is the gemara so sure that with respect to chovel we say that מקלקל חייב??

Ideas???

Lirfuas -  Chaya Gittel Feiga bas Beila Bluma bitoch shear cholei yisrael. כי חיים הם למצאיהם ובשרו מרפא