I think that this video is belaboring the obvious. Everyone has the right to not answer questions asked by the police. If you are under arrest and given your Miranda rights, all you have to say is you don't want to answer questions and that is the end of the story. The single biggest landmine people under suspicion run into is that of voluntary or spontaneous statements. Those can and will be used against you if incriminating...you'd be amazed how many people feel the need to bare their soul.
I think this lawyer might be taking it a bit to the extreme...what if the questions are for the purpose of investigating a crime that you are the victim of...are you going to "dummy up" and not talk to the police investigating? I think that might not work to your best advantage. Unless you plan on taking the law into your own hands, there is no reason to not speak to police if you are a victim.
My advice...use common sense and stay out of compromising situations!
TYA