The Self Destruct Button - S1-E7
Continuity mistake: At the beginning of the episode, Izzy takes a purple plastic cup of coffee with her to work. In the parking lot she now has a coffee in a disposable paper cup. Then in the locker room, she is back to having the purple plastic cup of coffee. (00:02:25)
Continuity mistake: Meredith takes over injecting George for Alex, and right after she stands behind George, Alex leaves. Just when he opens the door, suddenly you can see Alex is behind George and Meredith is just coming in again. (00:19:55 - 00:20:50)
The Self Destruct Button - S1-E7
Continuity mistake: While Meredith and Izzie are in the kitchen discussing Derek, Izzie sets the freshly frosted whole chocolate cake on the counter, but when she takes a seat in the closeup there's a slice of cake already on the plate, and in following closeups the cake is either whole again or back with the cut slice. (00:39:45)
Continuity mistake: When Addison introduces herself to Meredith, she reaches out to shake Meredith's hand twice.
Continuity mistake: When Derek is explaining to his patient about the risks of the brain surgery operation, Derek's hands move from his coat pockets to up near his chest, and back to his pockets. (00:30:40)
Continuity mistake: When Addison shows up at the end of the episode, the umbrella she holds keeps changing position and swapping hands between shots. (00:42:05)
Continuity mistake: Izzy tells the male patient she is a good doctor even though she was a model. Her hair is parted to the left and in the next shot it is parted to the right.
Continuity mistake: When everyone sits down for lunch, Izzy's bottle of water jumps from her tray to in her hand (as she drinks) between shots. (00:17:20)
Continuity mistake: When Dr. Burke tells the interns that he's chosen George to help perform surgery, Christina's arm moves from the table to up to her temple between shots. (00:09:50)
Winning a Battle, Losing the War - S1-E3
Continuity mistake: When Cristina leaves the room the brain dead man's daughter grabs her mother's hand. In the next shot, the mother and daughter are hugging each other.