Steve, those are cutting edge thoughts. First, are you sure that was a Showa among the Sanke? ...Or, was it a Sanke with Sumi on its head, and therefore a poor Sanke?
As the crossing of Sanke and Kohaku into Showa continues, a fundamentally different koi is being created. Showa Hi was different. Now, the "best" Showa are sporting Kohaku Hi. Showa Sumi was different. Now, the "best" Showa have Sanke-type Sumi. The Showa body shape was different. Now, the goal is to put a Sanke frame on the fish. At some point, the fish ceases to be Showa.
I think I disagree with Brady on the idea of a Showa being whatever is benched as Showa ... depends on the training of the benching team. Today, most benching teams seem to go by the presence of Sumi on the head and some Sumi rising from below in a band. Perhaps in time they will look in the mouth for black, and not finding any, declare the fish a hybrid belonging in kawari.
The old attempt to explain Showa as a black koi with white and red patterning never made much sense to me. The Sumi rose through the Shiro, so obviously the fish had a white ground. When I came to understand that Showa are from kuroki, I began to understand Showa. My understanding is still elemental, so I'm not quite ready to debate Brady on whether his New Age Showa are really Showa, or something different. I'm hoping to begin raising one of New Age Showa soon. So, maybe in a couple of years I'll be ready to debate it ... first I have to delve deeper into the essence of Showa, and only the fish can teach that lesson.