When Christina is turning around to look at the observation window in surgery, she has her head turned half way up, the camera angle shifts, and it is suddenly back down again and turns all the way again.
When Meredith is in the locker room talking to Christina and Izzy, she has "goo" from surgery on her left temple. When she sits on the floor a few Frances later, the goo is now on her right temple.
When Dr. Shepherd is getting ready for the hemispherectomy, he drinks an espresso after scrubbing and does not re-scrub before surgery. No surgeon would handle food or drink after scrubbing.
When they arrive at work near the beginning, as Meredith exits the car, and walks past, the boom mike is reflected in the car, in front of her, following her along.