I agree because it does it at strange times and it scares the poo out of me when it does. Or what we think are strange times anyway.I guess so but still a concern isn't it.
If it's doing it for parked cars then there could be a kid running out after a ball or an animal or something that normally you'd hit the brakes for anyway. On dual carriageways it could be a deer or anything. Technically it doesn't change anything (in my opinion) in terms of someone hitting the back of you, the difference to me is just that it may have made a mistake as to why it was braking in the first place.
Again, just my opinion and I have no idea what insurance companies would say.