100% true. If I was American I would plead the 5th under every circumstance. Over here, I would give a robust defence prepared by a solicitor and answer 'no comment' to every question they ask under caution. The police aren't your friends, they aren't having a friendly chat with you. They aren't trying to sort anything out in your favour and clear up misunderstandings. Even if they say they are - their job is to make you look as guilty as they can, and if you're innocent then protest, get emotional, contradict yourself or get flustered, it will be twisted as quickly as possible into a case for them. Say nothing. Be as compliant as the law requires, no more, no less.