Other mistake: The laptop used by Mr Perkins, boss at the Bank of Evil, has two W keys; the second key is between Z and X on the bottom row. (00:56:04)
Other mistake: When the ride finishes, there is no sign of a safety bar in Gru's cart.
Other mistake: While Gru is shrinking the moon the camera revolves quickly around the moon as it shrinks. When it cuts to the minions watching from earth, they have the same perspective as us.
Chosen answer: It is not very difficult to hold a straw between one's teeth, or gums and speak at the same time. A coworker of mine does it all the time with a pen.
MasterOfAll