If a person receives a subpoena and does not want to testify, do they have to give a reason? For example, let's imagine a person who was driving a car when it was involved in an accident that resulted in a fatality is subpoened to give testimony at an inquest. The person refuses to testify without giving a reason.
Can the judge then fine or imprison the person?
If the answer is "yes," then what is the recourse of the person? Can they appeal the ruling to an appellate court of some time and submit a brief that more or less that being forced to testify could incriminate the witness.
In other words, the fundamental question here is: Is it the judge's duty to recognize when testimony could be incriminating and excuse a witness, or does the witness have a legal onus to justify the refusal to testify, even when it is obvious that the possibility of self-incrimination exists?