I didn't just say "drugs being flushed," but included dangerous suspects. As it happens, most drug dealers also have lengthy criminal records for violence before they start picking up felony charges for drugs, and then they get habitual felony offender enhancements (for all their previous violent felonies), the amount and diversity of drugs they are ultimately caught with (each drug is a different charge), and random stuff like having the drugs in a Drug Free Zone.
Basically the entire war on drugs is a great way of getting rid of violent offenders for 20 or so years.
What person, and that includes cops, would not reach for a weapon when the door of their home is broken down in the middle of the night amid unintelligible shouts?
I've never heard of such a scenario actually occurring where criminals shout and break down the door. In a murder case I am familiar with, they used an agent in the house to unlock the door. Then they rushed in, marched the guy up to the bedroom, and then executed him.
I've also seen them go in through open windows, and stomp down doors only when they think no one is there.
But I have never heard of a case where armed men "shouted unintellegibly" and burst through the door.
Lastly, are there States where warrants are actually executed at night? I'm not aware of that being the case in Texas. I suspect that is not legal anywhere.
The risk of drugs being flushed is not worth the carnage that often happens with no-knock warrants.
The question is whether it is worth the occasional carnage that happens with no-knock warrants.