Hmm, this sounds interesting, but I don't want to just believe you.
I have set up a small script now which automatically compares and records the hashes before and after the roll.
If the phenomena is a s rare as you say it will take some time til I get a result.

Pure probability and statistic laws say that 14.5 out of 10000 results gives you one of the 4 highes winning classes which means on average every 700th roll will be of one of this classes.
I rolled now about 3300 times and had 3 results in these classes. On average I should have had 4.7 which is pretty close.
Statistically it could just be bad luck, but I'm curious what my recors say after another 1000 or more rolls.