No one should need to tell you that an easily measurable and obviously critical metric is wrong. You should have alerting in place for that. A difference of 95% to 0% should light up like a Christmas tree.
If you release a game that's impossible to win, you didn't do a meaningful amount of testing or QA when it hit production. I assume a dev played at least one game as a sanity check, but they didn't sit there and play until they won. A QA person wouldn't sign off on something if they only observed 1 of the 2 states it should reach.