Wow....I am thinking that Zincubus just enjoys arguing.
In my limited experience with breeding rats and feeding live...the rats are not threatened in the slightest by the presence of the snake. As already mentioned most will either go right to the snake and sniff it or just walk around the enclosure, heck I even had a few that would crawl right on top of a snake! Most captive bred rats don't even know to feel threatened by a snake.
I personally don't feed live anymore because I hate the smell and how dirty they are. I also only have a few snakes.