I feed primarily live, and never had a problem-because I supervise and remove the rodent if it isn't eaten within about ten minutes.

When I owned a reptile shop, I had several snakes, including balls, brought in over the years with horrible, disfiguring injuries from being gnawed by rodents. Some of these snakes died or had to be euthanized. This was ALWAYS the result of leaving prey in with a snake unattended. Often for 12 hours to several days!

Rodent injuries do happen but they are always the fault of the keeper.