Early on, after Larry and Jeff exit the initial HBO meeting and are walking to the elevator, you can clearly see Larry reach for the elevator button, hesitate, then move his finger up a couple inches and press it into empty metal above the button. This was presumably done to prevent the elevator doors from opening during filming of the scene.
In one of his stand-up routines Larry compares the freedom, of an American married man and a Chinese single man contending that the Chinese man cannot leave his country. This is a common misconception. Chinese people were not and are not restricted from foreign travel beyond the general need to obtain a passport which requires is a process similar to other countries.