[BS”D] When the doctor’s sons ripped their clothes.
A milah should only take place on Shabbos if there is a viable chance that one can start and finish it on Shabbos. Otherwise, the mohel should not begin to perform it. If he did, he just created a wound on Shabbos with no halachic justification. Other topics in this shiur: medical advice given by the holy Amoraim (and the sad reaction of the doctor’s sons); Milah on Yom Tov; Other halachos of Yom Tov, such as borer.