There just isn't enough time during a critical incident to remove this from the firearm. Officers need to be able to remove the firearm from their holster, aim and fire as quickly as possible - forcing them to retrain to remove the firearm, rack the slide, aim and fire will take hundreds of hours of re-training and I'd be willing to bet that officers will still draw and fire, jamming their weapons during a high-stress encounter requiring deadly force. Further, this adds too much time between realization of the threat and firing the weapon - even if you could untrain the instinctive response of drawing and firing.
With respect to private firearms ownership, your invention will do further damage to my civil rights - some moron like my AG in Maryland will think this is a good idea and pass a law making it a felony NOT to have one of these rounds in a loaded firearm. Just more governmental intrusion into my decision on how best to protect my family.
Thanks, but no thanks.