Comments by "Harry Mills" (@harrymills2770) on "Smart raven finds secret to happy marriage. He keeps bowing to his wife." video.

I think the bowed head is because her being next to him lets him relax for a minute. He's on high alert looking out for both of them the rest of the time. You look at the world from their point of view, and their behavior is totally understandable. I think most corvids mate for life and hold funerals for family and clan. If they had hands, they'd be dangerous.
1