There is a point. I understand your friends point though. In the USA, not giving them permission allows your lawyer to fight the case on the ground that it was

There is a point. I understand your friends point though. In the USA, not giving them permission allows your lawyer to fight the case on the ground that it was an illegal detention. Case law has set precedent that without reasonable suspicion officers cannot extend your detention in a traffic stop just to bring a dog in(Rodriguez v united states 2015). Never ever give permission to search.