This little episode might illustrate Phillip's lack of understanding of the modern world. I think there have been great efforts behind the scenes to adapt the Royal Family to modern media and a need to appear to have more of a personal connection with people.
As very few people make any contact with the royals in person, the media will dictate what actually happened, and how. Now we have a story, flash in the pan or otherwise, which could eclipse what the pre-planned story of showing respect to BoB veterans was supposed to be. I don't think you'd ever find Liz being either so crass, or so sloppy.
Of course, it's only the latest example of a very long string, but for the rest of the family I think the public reactions after Diana's funeral marked a turning point.