"When I have cruise control on and I have to slam on the brakes I expect my car to stop. I don't expect the cruise control to keep it going at the same speed. I wouldn't realise I needed to turn it off manually before an emergency stop unless there were a fucking big warning sign on the windscreen. And if there was I'd not drive it on the grounds of "that's fucking ridiculous"."
Your anti-lock braking system (ABS) system will cut out the breaks though, this situation is similar to if your car's lock-up sensor malfunctioned and your ABS decided to disengage the breaks to try and correct it.