Dr Richard Webber dismissed the surgical resident offscreen in the April 30 penultimate Season 22 episode after confirming Kwan gave a patient an experimental treatment denied by the FDA.
Webber told Dr Miranda Bailey, who had previously taken the blame for the incident, leaving Kwan's future on the ABC medical drama unclear before the finale.
The shake-up comes as longtime characters Owen Hunt and Teddy Altman are set to exit after the Season 22 finale, with Thursday's episode ending amid a possible fatal bridge collapse and crash.
How do ethical dilemmas like Dr. Kwan's firing shape the show's portrayal of real-world medicine?
Will 'Grey's Anatomy' resolve Owen and Teddy's fate, or are their stories truly left open for future returns?
Could the departure of legacy characters signal a creative turning point or risk alienating longtime fans?