Well, this assumes the guard actually existed. The Wikipedia article could just be based on an imaginative kid telling a made-up story to his brother (although the kid would have to be quite knowledgeable to know about the historical events, as well as the details like differing uniforms); the story has spread that it's become, as the article says, folklore.
There are churches in the world that's been built because some people (usually young girls) said they saw the Virgin Mary...
There are churches in the world that's been built because some people (usually young girls) said they saw the Virgin Mary...