Continuity mistake: Dr. Warren pulls off his face mask. The camera pans to Dr. Bailey for about a second or two and then back to Dr. Warren, whose mask is back on. After panning away again for a few seconds and back, Dr. Warren's mask has been removed again. (00:11:30)
Other mistake: There are two mistakes when Grey is at the computer trying to figure out why her patient is having seizures. The camera pans out showing Bailey walking up - if you look at the computer it shows a login screen, but when Grey shows Bailey the screen it changes. Next one is when Grey blows up the pic of the taratoma - when they leave the picture on the computer it's actually a brain.
If Only You Were Lonely - S8-E16
Continuity mistake: When Richard Webber hears the smoke alarm, he is in bed in his pajamas. The next shot shows him in the kitchen putting out the fire in his work clothes.
The Lion Sleeps Tonight - S8-E18
Other mistake: At the beginning of the episode, when Meredith, Derek and Zola see the lion crossing the street in front of the car, the lion roars and it is clear that the lion is not missing any teeth. However, later in the episode, Richard removes a tooth that had gotten lodged in the male mauling victim's arm. The victim was the lion's owner and the attack happened in his house, so by the time the lion was out the tooth should already be missing.
Continuity mistake: Avery and Kepner are at the bar. Keep looking between them (over Kepner's left shoulder). Right when Kepner says "I'm a soldier" a guy in in the background comes around the corner wearing a dark shirt with what looks like a red vest/sweater. The camera changes to a different angle for Avery's line, and then when it comes back to Kepner for her next line, the guy in the red sweater/vest comes around the corner again. (00:16:00)
