When XCom craft is destroyed by Hunter-Killer ufo, pilots and passangers usually get a chance to survive and end up transferred to home base. But when "Disengage" button is pressed, they never escape.
I believe this happens because "Disengage" button sets _end field to true, and then check at DogfightState.cpp:1444 skips call to evacuateCrew (sorry, forum does not allow me to post github link).
Attached save for Piratez with craft types edited for demonstration. Intercept ufo, get shot to last bits of health, press retreat. There will be no gals in transfer, and no "Vessel lost" message either.