Diplomatic row after Russian Spy poisoning case continues.

The transcript consists of a brief statement expressing uncertainty or lack of knowledge.

What does the phrase 'No, I don't know' imply about the speaker's knowledge?

In what situations might someone respond with 'No, I don't know'?

How can the response 'No, I don't know' affect a conversation?

What emotions might be associated with saying 'No, I don't know'?

How can one improve their response to questions they don't know the answer to?