Carbon fibre isn't a metal so this would not achieve anything. I would suggest that posting on the cycling forum on Boards.ie will provide the best opportunity to receive practical advice from posters who will have seen and/or experienced similar damage on Carbon Fibre frames. In general my understanding is that after a crash or impact an x-ray or scan of the frame can be required to establish if it is safe to ride or needs to be replaced.
Yeah, you'd need to do a CT scan of the affected area to determine the extent of damage and form an opinion of the cause. Canyon in Germany offer this service and will look at other brand's bikes, but that'll cost €300 plus shipping back and forth. Since they started using CT scanners, a few other manufacturers have followed suit, but these are €500k+ machines, so getting to use them isn't cheap.
The Boards suggestion is a good one, there are a few on there in the business and will be able to recommend someone who can do a more authoritative examination and help determine if the failure was due to a manufacturing fault or a knock.