New Jersey case allows minor impact photographs

The New Jersey Supreme Court has allowed photographs of a minor rear end collision to be admitted into evidence on the issue of causation without the need for expert testimony.  The battle will continue as to whether photographs showing minor or no damage to vehicle will be admissible to either prove or disprove a cause and effect injury from the accident.  The reasoning is interesting because it concludes that everyone knows that small impact equals small injury, great impact equals great injury. While this is the usual argument, I would like to know on what foundational base that opinion is based.  It appears that the acceptance of the conclusion may not be correct or based in any scientific fact according the biomechancial studies. How many people walk away from horrendously bad impact accidents without being hurt?