A good thing that they know this: the Law does say you need to call the director and correct. Most don't - they just correct it. They should - not only is it the Law, but this is a situation where others need to know what their rights, responsibilities and options are (and the director would like to know what they would have done with the correct explanation).
Players do not have a right to talk to the director during a hand away from the table. Look, you can ask. Whether the director will agree is another story. Whether it will help is yet another story.
The problem with "call the TD, ask to speak to them away from the table" isn't that it's not legal; it's that it passes UI. In this case, it's not going to be a problem; the TD will say, "yes, come back, correct your explanation now, and we'll handle what happens from there" and the AI will cover the UI. Really, the "99% time" it's a problem is when it was "partner misexplained and I'm/she's on lead, what do I do?" because now the answer is "nothing until the end of the hand, but you've already told partner about the misexplanation; so now she doesn't get to wake up on her own, she's constrained by UI."
Best if the players just know the three cases without having to "talk to the director away from the table":
- If you misinformed, call the TD and correct immediately (okay, before the opening lead. But immediately is better).
- If partner misinformed, and you are dummy or declarer, correct during the Correction Period (after the pass, before the OL).
- If partner misinformed, and you are a defender, wait until the end of the hand and then call the TD and correct (assuming the TD hasn't already been called by declarer!).
When I go to sea, don't fear for me, Fear For The Storm -- Birdie and the Swansong (tSCoSI)