The rule says to put a question mark at the end of a sentence that asks a question. In reporting, our questions are not always straightforward. Attorneys add things — explanations, clarifications, suggested answers. Taking all of those into consideration, I would have us tweak the rule a bit and word it to read:
Put a question mark where a question is FIRST asked.
(Note standard “pre-“comment here: We LOVE attorneys. They make our living.)
My clue to you is always this: At the point that the attorney could put his index finger in his mouth and not go on, giving the witness a chance to answer a perfectly valid question, that is where the question mark goes. Then let the rest of it stand on its own — even when it is a fragment.
…Q Who was with him? His sister?
…Q When did you see him? I am referring to on the Friday that this incident occurred. (or question mark depending on intonation)
…Q Was she there with him? Do you know?
If we do not use this modification of the basic rule, we have commas and dashes and semicolons after questions. I just don’t think that works.
AND this gives us a means of being consistent in the way we handle questions.