I don't have to provide evidence. It's common sense. Scalding hot food down the gullet of a snake can do irreparable damage to and quite possibly kill it if hot enough. Just as common sense also denotes that leaving a live animal with a snake unsupervised could spell trouble. There are pros and cons to everything in life. This is really no different and honestly, it's a choice. If everyone agreed upon the best methods for their lifestyle, there wouldn't be choices.

Put the live rat/mouse back in a holder tank with some food and water until the next feeding attempt. About as simple as throwing away a thawed rat/mouse if uneaten and thawing a new one at the next feeding attempt.