When Casey and Sara are examining the footage of Chuck and Morgan, they zoom in on the tickets for the Concert they are attending. You can clearly see the seat locations as D9 and D10. However, when you see Chuck an Morgan at the concert, the seat behind Morgan is labeled 126.
When the doctor fills the syringe you can see an air bubble inside of it. He never expels the air prior to injection, potentially causing an embolism and death.
In the opera, the orchestra on stage is too small to be playing Beethoven's Ninth Symphony.
At the opera, the two violinists are playing their bows on air rather than the strings.