As said, it's just stressed rubber from overheating and being pushed too hard. Doing track day riding on streets, with everyday tires doesn't make the rubber happy. Don't matter what bike you ride you'll always get the same result if you push them. Your worry is you do this kind of riding a lot, so knowing how long your tires are going to last isn't easy.
Because the tyre is of a block pattern the blocks move around under high loads and the tyre heats up very quickly, makes them look like the pics! The old style wet weather tyres worked on the same principal
Your right, the blocks did move a bit. Everything is starting to settle back down now after a couple of days riding. The tracks the only place my front tyres looked like that. I'll be there for the next round thats for sure. That was crazy, adrenalin charged fun. after every session I was shaking.
My employment agreement, clearly states, that: under no circumstances ... 'should a firearm be brought onto corporate property'.
I'm guessing Mr. Waters' workplace agreement goes one step further ....