I started a thread just a little while ago that asked about this but no one responded to this part as it also asked about crit rating and that is what people responded to. I only did a little testing but I was certain that pressing attack was critting less. If the first attack cannot crit then things make sense. It may be the case that the way the code is written that any crit on either hit would trigger the defeat response. If that is the case it makes sense for them to take away crits on that first hit as double the chance makes pressing attack incredibly powerful.