Actually I missed a few things. Both sides should be allowed to do the following: Refuse to answer a question (except asking the police to see a copy of a warrant or their police identification (they can refuse you to touch their police identification though)), or claim to not know something or forget something (even if that is untrue). And if someone nevertheless says something untrue even in a way which is not permitted, if there is a reasonable chance to believe it would be inadvertent, then they are forgiven (and if they are the police, may be allowed to try again later (if the person they are interrogating is still a suspect), even though the first attempt at arresting them didn't count).
