Seems like this has grown into quite the discussion.
Now here's more food for thought, something I don't recall anyone posting as a point, although have seen another point mentioned, that is, snakes eating live in the wild as if it is all they eat in the wild.
In the wild, all animals, including snakes, are creatures of opportunity when it comes to food and feedings.
Even the parasitic animals such as the hyena, wait for another animal to do the work for it, devouring dead prey just as they would live prey, if they needed to catch it themselves.
Snakes also eat like this, primarily due to food having varying degrees of scarcity in the wild.
One season may provide an abundance of food, while another season may not.
Another season may provide too many prey items that will die of starvation or disease. If so, then snakes will still eat dead, as the opportunty arises.
Food is food, dead or live in the wild and with snakes being masters of conservation will eat dead in the wild as another means of conserving energy.
It's a free meal per say.