As part of our document checks before departure either to or from the US, we need to see the General Declaration to ensure that is correct. After reviewing the document, I sign it and give it back to the Senior Cabin Crewmember so she/he can hand it over to the ground handler upon arrival.
As for the behavior of this captain, on the surface, it appears that all his oars were definitely not in the water.
I can't believe that anyone would divert a flight, especially and international flight, becuase a request was not complied with. I can't wait to hear the true spin on this event.