Charles says he doesn't treat patients who graze but in an earlier episode he helped Mrs. O'Reilly birth a calf over the radio
Charles demonstrates the drug Levophed, which is being used for the first time - but the nurses were using it during Season 8.
Margaret: Tomorrow I'm supposed to deliver a lecture to my staff on the administering of Levophed and I wondered whether you'd do it for me.
Winchester: Margaret, correct me if I'm wrong, but what you're asking me to do sounds dangerously close to nurse's duty.
Margaret: Yes. But, you see, I was supposed to go to Tokyo tomorrow.
Winchester: Margaret, even Winchester women do not do women's work.
Potter's remark "I don't know nothing about birthing no bovines" is a reference to the iconic 1939 film Gone With The Wind, when Prissy told Scarlett "I don't know nothing about birthin' babies".