What they mean by "carbon fibre 12" is probably CF-filled PA12, a nylon. PA12 CF has a maximum working temperature up to 170C, vs. (for the two most common filaments) ~80C for PETG and ~60C for PLA.
The thing is, everyone who has been printing for more than a couple days should be familiar with all of this. It's honestly shocking that they'd use a material that doesn't tolerate the heat in question. Did they not know how hot it was going to be? Was there a chain of miscommunication, where the person who did the print wasn't told how hot it was going to be by the person who requested the part? Or was the printer just a moron?
While this is being used as an anti-3d-printing story, I think the real problem is just that 3d printing makes manufacturing so much easier, that a lot less is being done by engineers and more by amateurs who often aren't as diligent at studying what a problem actually needs and work more by guesswork.