Many of the female surgeons will wear jewelry while scrubbing in, as well as while operating. This is prohibited in real Operating Rooms. Also, many of the surgeons (especially Dr. Maggie Pierce -Kelly McCreary) have long nails which is a no-no for a surgeon.
Masks are commonly down while in the Scrub-In room. All surgical personal are required to have masks on before entering the Scrub-In room or OR in real operations.
Throughout the series, the Chief of Surgery is shown as running the hospital and surgeons are depicted as making diagnoses. In reality, the Hospital would be run by the Chief Administrator, with a Chief of Medicine and a Chief of Surgery reporting to them. Diagnosis would be handled by medical doctors who would refer the patient for surgery.
The heads of all the major surgery departments, especially those like plastics, would not be hanging around the ER waiting for cases, but would only come down in unusual cases.
The heads of surgical departments and attending surgeons are portrayed as middle class income earners who carpool and rent living spaces. Surgeons are generally one of the highest paid professions in the USA.
Time after time, the female doctors get "unexpectantly" pregnant.
Do none of them know anything about birth control?