Continuity mistake: When Jerry's sitting with George in the hospital talking about George's jacket, as Jerry says "no, I tried it on, it fits good", he's gesturing with his left hand, which he then puts in his lap. From the reverse angle though, his left hand's still raised, then he lowers it again.
Continuity mistake: The doctor is examining George. George yells into the stethoscope so he takes the buds off his ears. Not just that; he removes the instrument and puts it around his neck. George then freaks out and starts naming various odd and even rather harmless conditions; the doc is wearing the stethoscope again. Flirting with Elaine you can see the instrument sorta shuffles around, with part of it exposed and part of it under the scrubs' collar, now the left side, now the right side. When Jerry breaks off their idyll with the Romeo and Juliet reference, the stethoscope is back around his neck, only to be again in use when George asks "With a knife?" (00:08:00)
Continuity mistake: On his deathbed George triumphantly utters "There's nothing wrong with me!"; the doctor cools his enthusiasm down though, saying that he wouldn't go that far. His hands are crossed in front of his body - at the cut though he's suddenly already browsing through George's medical file. (00:08:10)