I'm assuming you do not pounce on your dinner when you eat it, nor do you beat it into submission before consuming it. Why? Because you don't need to.
Most animals are much smarter than we give them credit for. While instinct will compel them to do some things, in many cases, our pets are no more inclined to work harder for their meals than we are. Why strangle something when it's already dead? If the prey isn't struggling to get away, why waste the energy subduing it?
While we tend to think of animals in definitive terms, i.e. an animal is a predator or a scavenger, in truth, most predators are "opportunity" feeders. Scavenging is not "beneath them" when the opportunity for a "free meal" presents itself. The only reason they don't scavenge more in nature is that the opportunity to eat something that is already dead or nearly dead rarely presents itself, as the predator that caused the prey's death is usually close by waiting to consume the meal themselves. Prey animals that die of other causes are greatly outnumbered by the creatures that will consume them.
If your snake is feeding regularly and is healthy and growing, you're ahead of the game already.