I would deffinately reccomend a necropsy on the snake to ensure no other factors involved such as any mite & tick sprays that may have been used on or near the feeders as a preventative or nuerological problems.
From the desription, I am leaning towards a nuerological reaction to something that really needs to be determined, such as disease or toxins.
I seriously doubt that the prey revived inside the snake, even if it was merely unconscience due to the massive squeezing it recieves during the act of swallowing. along with a lack of any breathable air.
As for a very possible nuerological reaction to a toxin, or disease, I would deffinately want to know for sure as to prevent any more deaths due to an unknown factor.
Why risk the entire collection over tainted food sources or an illness not yet detected?
P.S. PLEASE PLEASE PLEASE ONLY USE LIVE PREY AS FIRST MEALS FOR BABIES
This I do not agree with. Many snakes, colubrids up to boas and pythons, will take dead prey as the first meals.
Besides, this phrase really doesn't fit well with a post about a possible death due to live feeding.(necropsy needed!!!)
Start them on dead and you will have better odds at retaining them on dead.