what happens when a P is contributorily negligent ina case where the D is negligent per se?
why wouldn't it be a defense (well, counter-defense, really)? you can use contributory negligence after being proven to be negligent, why would it matter how you were proven to be negligent? there is no reason a defendant can't claim contributory negligence even though the defendant is negligent per se.
For negligence per se you must establish: 1) Violation of a statute: 2) plaintiff was in the category of persons protected by the statute; 2) the harm was the kind of harm the statute was meant to protect against. Remember you need each of these elements and not simply a violation of a statute.