That is not correct, as I stated earlier, if a company was using the technology that was deemed an inside or trade secret function to that company but did not have a patent on said technology, that does not constitute prior art, thus it would not invalidate a future patent as you claim. There is only one way a company could invalidate a patent in that case and it would involve litigation against a former insider or employee who then took the technology and patented it. That's it, that's all... If someone else independently patented a technology, it is not automatically invalidated.