But there are times when the lawyers/barristers/etc. cannot possibly know about that. Only the one being questioned, at times, may know whether or not a particular question with its honest and full answer might lead to self-incrimination. For example:
Lawyer: "Where were you at 10PM, last night?" Respondant: "I invoke the 5th Amendment."
Certainly, it is possible in this case that the lawyer may have no idea at all that the answer might tend to incriminate the person, unless they were already informed about the possibility. And even then, they might not know for sure until they ask. But as bad as this example may be, there must certainly be times when only the person being questioned really understands the fuller implications and possibilities in answering honestly, in terms of self-incrimination, and therefore would need to speak out for themselves on it.
In those cases, how would a person respond under British law? I'm curious.
Jon