While that's true, over a large enough sample size it should regress back to the 72% success rate. If you were to double DSN's sample size (original being 513/1000 or 51.3%), that would mean there would have to be 927 successes out of the next 1000 (92.7%) to get back to the proper success rate (1440/2000 or 72%). Even if you double that sample size to 4000, DSN would have had to get 2367 successes out of the next 3000 (79%) to get back to 72%.
Further, if you evaluate the 207 extra fails from the original use case in a vacuum, the odds of that many fails at a 72% success rate are astronomically high. So high in fact that you have a better chance of winning the PowerBall lottery (1 in 175,000,000) 13 times in a row. [Disclaimer: While I did do the math to get the odds, I'm not statistically versed enough to determine if I incorrectly evaluated the 207 fails]
The point is, it doesn't seem like the math is right. It could be either the algorithm to determine success or fail or the way the game calculates the stated success rate to you.