...but if not, consider what would happen if the captain then decided to taxi the aircraft clear of the position it had come to rest? Increase in power to move might very well ingest a fwd chute and the fan thrust would almost certainly rip any rear chutes from the aircraft.
We have this covered in our standard procedures, wherein, in the event of the scenario you described, the Captain (or another FD crew member upon direction of the Captain) shall make an immediate PA announcemet (once the aircraft is stopped) to the effect of...'Cabin crew, stand by for further instructions, cabin supervisor, report to the flight deck.'
In this way, we hope that the unpleasant situation you have described, can be avoided, as much as possible.
One day, many casualties will result from just such an event and the Industry best practice will be altered.
I expect you are quite correct.