It's technically possible, but in practice that's never how it works. The entire purpose behind no-knock is to take them by surprise before they can even think about resisting. They use immediately overwhelming "non-lethal" force so that they never have to escalate to a "lethal" level. Obviously the definitions of these terms are imprecise at best.
Believe it or not, this is the safest way to do "no-knock" for everyone involved. Think about it- if a law-abiding gun owner was woken up to the sound of unknown men breaking down his door and had time to access her weapon, the situation would be much worse for everyone. There have been many instances of this exact thing happening, often resulting in the death of the raid victims and/or police officers. That is why stun grenades are always the first thing that goes into the building during a no-knock raid.