It was nearly December. I wonder why John-John had to wear shorts that day instead of long trousers and Caroline had to wear short socks instead of knee-highs or tights. They were probably cold.
I'm guessing for the same reason that Jackie didn't change out of her blood-splattered pink outfit on that day from hell.
It wasn't all that blood splattered, considering. The back of her outfit evidently wasn't blood smeared either, as would be likely after she moved back to the seat of the car where he had slumped over. I'd rather not discuss it at this time, though, because I know the boundaries of acceptable debate about the subject don't extend that far for such unorthodox questioning and I'd rather not get "electrocuted" or blacklisted over it.