Czuch: "Is it against the rules here to have a program assess a situation to help determine the probability to get a gammon or if a double should be offered?"

For sure. You should only analyse a chequer play or cube decision, after you've made it. Same with discussing it here.

"It is a good example tha a back game can win, but that will only happen once every 25 situations or so, although that number seems too high to me."

That 1/25 is much too low. Have a look at those numbers again. Sue had a 1/10 chance even when you were down to your last 6 men. With a double-anchor back game your chances can be as high as 30% and is why you should be hesitant about doubling if you're winning and ready for the cube if you're the one playing the back game.