Reminded why I breed feeders

[MrLang]

This could also be bad news even for the freshest kept frozen feeders. if the water is hot enough it could easily degrade the skin and outside of the feeder.

This. I would say your thawing practices are at fault here and not the rat you bought. Plenty of threads go over the 'proper' way to thaw, but I think in general you will find you are going to have a bad time if you thaw directly in the water whether from this or from the body exploding on strike.