"You Know What You Did" was met with generally favorable reviews from critics, who felt that the changed dynamic between Conrad and Montag was entertaining for television. Writing for "Entertainment Weekly", Jennifer Armstrong provided a favorable review; she opined that the conflict between Conrad and Montag made for the "most mature season ever" and offered a disclaimer that the term "maturity" was "being relative here, of course." A writer for The Hollywood Gossip stated that the episode "didn't disappoint", and felt that the storyline clearly categorized Patridge and Port as being part of "Team Lauren" and Pratt as being part of "Team Heidi" in the "epic war".