While judges are trained to judge each of the three categories independently, and we all try to do so (I hope), I can't help but believe that each category effects the other even if subconsciously, and even if only a little.
When competing, I have found that the better my presentation scores are, the better my taste and tenderness scores are, even though I'm using the same recipes, meat sources and processes. There could be several reasons for this, like it landed on a high scoring table, or I just happened to get a good tasting chicken, cow or pig, or I drank a little less that day and was on the top of my game, BUT...
There's a saying, "You eat with your eyes first". If something looks unappealing, subconsciously you might be predisposed to think it tastes unappealing. Conversely, if it looks great you might subconsciously believe it tastes a little better.
I also believe taste and tenderness are similarly intertwined. While perfectly tender meat could taste terrible, it would be very difficult for a tough piece of meat to 'taste' a nine. Taste is a subjective term that includes flavor, aroma, personal preference, mouth feel and many other things. If it chews like leather, it would be extremely difficult for even outstanding flavor to fight through the judges unpleasant experience.
People are not computers. Try as you may to keep things fair and keep each category separate, your subconscious might not cooperate.
Just sayin'...