When Prince William failed to bow to the newly crowned Queen Camilla during the Coronation, it was an example of the Prince of Wales following his gut instinct and potentially subconsciously siding with his late mother, Princess Diana, a body language expert says, per The Mirror.
The move was actually a break in royal protocol, but body language expert Judi James says William might have found it unnatural to bow to his stepmother, who had an extramarital affair with his father, King Charles, throughout the majority of his marriage to Diana. The Mirror points out that William was not alone in this, and that the majority of the royal family bowed or curtseyed to the King only. Royal protocol states that royals of a lower rank must bow or curtsy to those in a higher rank—so William and basically all of the other members of the royal family should have bowed or curtseyed to the new Queen.
While the possibility does exist that he had already bowed earlier in the day off camera and didn’t feel the need to do so again, James says “Would William have felt comfortable bowing to the woman who took the place of his mother on the throne of the U.K.? He turns to look at his father but avoids looking at his stepmother.”
James calls this “a unique example of selective bowing,” noting that William and his two eldest children Prince George and Princess Charlotte also opted not to bow or curtsy to Camilla.