Rattled can very easily mean head injury and that's as real as it gets. Your bruise could turn blood clot turn aneurysm and then not documenting the accident would be a huge legal/financial drain on your survivors.
Ditto on the cops calling as a precaution. Friend of my wife was hit by a car and "not hurt". Never got checked out. Two months later he died suddenly in his sleep. Related? Hard to say but he was 44 years old and in excellent health (triathlete, karate) so it was hard not to think the 2 were somehow connected
