In fact, he says that no one should ever agree to be interviewed by the police. Take the 5th. Even if you're innocent, speaking to the police will never be to your advantage. What you say can and will be used against you in a court of law--but it cannot be used in your favor as it's just hearsay.
About halfway through the video the professor turns over the mic to a police officer who, rather than contradicting the professor, actually augments the professor's arguments.