No offence, Paddy - but to me you come across as obfuscating on this. I don't see any evidence in the DES publications to indicate that it would be inappropriate for a board member to raise the issue of a principal's absence at a BOM meeting for clarification. Indeed, there is a a specific responsibility of the BOM to communicate with parents outlined in the DES publication, so this could easily have been addressed by a simple notice in a newsletter (e.g. 'best of luck to Principal Skinner who is taking little Miss Skinner to compete in a father/daughter breakdancing contest').
If there is something specific out there that would go against this, please give specifics.