I think a lot of times in discussing various events and who curtsied to whom and who bowed to whom gets confusing because there is a mixture of protocol of what is expected and just plain old courtesy and respect.
Although its a dwindling practice, there are still times a man opens a car door for a woman (my hubby still does this) and pulls out a chair to seat a woman and there's always families that have "Dad" at the head of the table.
Then again, it might also be a truism that comes from the Duke of Edinburgh who smartly quipped "When a man opens a car door for his wife, it's either a new car or a new wife." (On a side note though, hubby and I have been married 19 years this month and own a older, very used vehicle but then again, we're practically dinosaurs from an age past.)