When you are hot and high, you are in the same position as an emergency descent. Max speed, max speed brake, idle descent. I flew that today to get down (5000-6000fpm down). Rarely used (sometimes it makes sense) and often brings an ECAM caution on the bus because the cabin repressurisation can't keep up. I would suspect the key clue to a passenger would be some other event eg. call cabin crew to station, obvious loss of cabin px, smoke in cabin, combined with the above.