Dutchroll
That's a bit of a silly point of view from CASA (yet unsurprising all the
same), given that you've finished all your operating duties and are not
scheduled for any more. By their logic, the fact that we can be phoned at any time of the day while at home and asked to crew a flight if we answer the phone, means we can't have a beer or glass of wine....ever!
He was still on duty and available. Taking a call at home doesn't mean you're on duty.