My interpretation is that this was not "obviously designed to be gamed with secret information", it was just bad methodology. They had a goal of screening out 70% of applicants, but the remaining 30% of applicants needed to have a demographic balance that would not constitute a disparate impact, and they had to do this in a legally defensible way. Working backwards from that goal, they took biographical data that they had collected in the 80s and 90s and constructed a test program that, they believed, would give them the result they wanted. So if the answer weights are logically nonsensical, it's not because they were building in a secret password, it's because that's what happens when you build a model that's overfit on a small number of datapoints.
https://storage.courtlistener.com/recap/gov.uscourts.dcd.182...
https://www.courtlistener.com/docket/4542755/139/24/brigida-...