Factual error: Most of what Will says about the Challenger's O-rings is wrong. First of all, he says they are meant to keep hydrogen from leaking out of the SRB. SRB stands for Solid Rocket Booster, meaning they use solid fuel, not hydrogen. The hydrogen was in the external fuel tank. Second, the O-rings were tested for cold, and NASA engineers recommended against launching that day, with one of them even refusing to sign off on the paperwork if the launch was to go forward. NASA overruled them and went ahead with the launch anyway, with all the disastrous consequences that ensued.
Factual error: The General wants to do his interview by the TV so he can watch March Madness at the same time. When the interview is about to begin, it shows a Kentucky game being played on Kentucky's home court. Teams cannot play on their own court during the NCAA Tournament. (00:40:50)
Continuity mistake: When Don and Sloan are in her office discussing the economic tip, Sloan's hair repeatedly jumps from straight down to tucked behind her ear.
Revealing mistake: When Elliot and Maggie first arrive in Boston and Elliot begins reporting on the 31 injured patients, in several shots Maggie is supposedly on the phone with Jim back in New York. In each shot if you look closely you can see her iPhone's screen is lit up and is on the home screen, meaning she isn't actually on the phone.
What Kind of Day Has It Been - S3-E6
Factual error: The limousines carrying everyone to the funeral have New York plates but have white TCP numbers. TCP stands for Transportation Charter Party / Transportation Charter Permit. This is issued by the state of California and only California. New York permits have a different decal / designation.
Continuity mistake: The stock footage of the airplane that Don, Sloan and Elliot are on is of a Boeing 747, a very large widebody plane. However, the internal shots of the plane suggest that it is actually a much smaller narrow body plane. (00:13:55)
Audio problem: In the Juilliard scene, the vocalist is singing the Schubert Ave Maria but the music on the piano is the other famous Ave Maria, the one set to music by J. S. Bach.