Sports aren't an "on" or "off" proposition, but something which occur along a continuum. I view it as if Spray is an intermediate mutation between the original bush and the extreme climber. You can find Spray with and without the elongated sepals, just as you can find variations in the climbing sport which flower nearly continuously all the way to once flowering, like a traditional rambler. Thomas wasn't the first to be fooled by the variability. It's as if he observed all he could and attempted to determine what differences there could be between two identical plants in hopes of figuring out what the difference actually was. As has occurred with the identification of many species, he observed repeated characteristic variations and proclaimed them different, when they were actually variations of the same thing.