That line of white words turns out to be like this. This task has been completed. I understand. Thank youOnly from the screenshots, it looks like you won already. 17/17 baddies down, and it says "Press Tab to exit".
Was Tab not working to end the mission?
If Tab is working normally, but you're wondering about the white letters, it just means all of the hostages are still alive. If you kill any, then it gets crossed off and you lose.