It's true that if he said nothing he might have been taken to jail for 8 hours instead of being detained for 3.5 hours. But it's also possible that he talked and talked until eventually, under stress, he said something stupid that led to a conviction with a 2 year prison sentence. It's basically just a gamble with your life.

There's nothing wrong with being polite, but insistent on having a lawyer with you when you speak to the police. Tell them that you will be happy to talk with your lawyer present.

If the police are questioning you then there's an excellent chance that what they are really trying to do is to build a case. The more you talk, the more things can be used to make you appear guilty in court - even if they don't seem significant to you. That is why you don't talk to the police - even if it means sitting in jail for a day.