I have investigated the dive above with the help of (diver's name retracted) and the reason is simple: Laurent has used AIR mode for this dive This is important information, as AIR mode is just a simplified mode for OWD recreational divers and in this mode, the conservatism is totally controlled by adaptive conservatism mechanizm (we assume that OWD/AOWD divers know nothing about GFs). So despite he set GFs to 85/80, in AIR mode GFs were controlled by adaptive conservatism mechanism.
What does it mean? Laurent has done dive in AIR mode, so the GF's were set for 70/30 and because of that BLACK gave longer deco time than OSTC and PETREL.
We have simulated the dive in TMX mode with the GFs set to 85/80 and it gave exactly the same results as OSTC and PETREL.
So in our opinion there was nothing wrong with the algorithm of BLACK, but it just been configured in a different way. If the mode would be set to TMX (which use GFs set by user), the result would be exactly the same as in PETREL and OSTC.
Sorry for confusion. For us it's a lesson that we must put more attention to give more precise information in the manual. Of course the next edition of the manual would be improved.