One, had. Starliner went home. Two, they didn’t. Starliner was broken. Its manoeuvring thrusters, a critical reëntry system, were misbehaving. If you’re on a plane and the oxygen system fails, that’s an emergency. You don’t have to wait for cabin pressure to fail for it to qualify, and oxygen systems aren’t even a critical system; this is closer to the flaps or landing gear behaving erratically.