I think your buddy thought he missed 10 questions. I don't think anyone from PSA told him how many he actually missed or for that matter which ones. When I interviewed they would only tell me I did not pass the test and would not tell me how many or which ones.

The truth is they control the process so there is no way to prove you did or did not pass the test. You have to take their word for it and hope that they are not using this as a tool to weed out a candidate for one reason or another. I choose to believe that the process is fair and reasonable and I was not as prepared as I should have been regardless of whether the gouges were right or not.