Thanks for the explanation, but in the moment the parking brake did actually seem to help. I was nearly stopped, so the lockup of the tires gripped instead of just sliding. Fortunate timing as I understand what you are saying about the anti-lock being a quicker stop in most cases. This little extra brake action did seem to stop the car faster this time though. What I think it did more effectively was to stop my car from hitting him harder upon impact from behind. At least I think the emergency brake would help a little in that situation too, but maybe not.
